{"gene":"TTF1","run_date":"2026-04-28T21:43:00","timeline":{"discoveries":[{"year":1991,"finding":"TTF-1 (a homeodomain-containing transcription factor) activates thyroglobulin and thyroperoxidase gene promoters in differentiated thyroid cell lines, and its mRNA/protein show clear nuclear localization in thyroid, lung, and restricted brain regions from the earliest stages of organ differentiation.","method":"In situ hybridization, immunohistochemistry, promoter activation assays in thyroid cell lines","journal":"Development","confidence":"High","confidence_rationale":"Tier 2 — foundational study with multiple orthogonal methods (ISH, IHC, reporter assays), widely replicated","pmids":["1811929"],"is_preprint":false},{"year":2004,"finding":"TAZ (transcriptional co-activator with PDZ-binding motif) directly interacts with the NH2-terminal domain of TTF-1 via its WW domain, and this interaction synergistically activates surfactant protein-C (SP-C) promoter transcription in lung epithelial cells.","method":"Mammalian two-hybrid assay, GST pull-down, co-transfection luciferase reporter assay, deletion analysis","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 1-2 — reciprocal pull-down plus deletion mapping plus functional reporter assay in same study","pmids":["14970209"],"is_preprint":false},{"year":2001,"finding":"CBP/p300 and SRC-1 interact with TTF-1 in vitro and in lung type II cell nuclear extracts; PKA-mediated phosphorylation of TTF-1 facilitates this interaction and leads to TTF-1 hyperacetylation, enhancing its DNA-binding and transcriptional activation of the SP-A promoter.","method":"In vitro GST pull-down, SRC-1 immunodepletion from nuclear extracts, transient transfection reporter assay, PKA catalytic subunit overexpression, adenoviral E1A competition, cAMP-induced acetylation assay","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 1-2 — multiple orthogonal biochemical methods in one study demonstrating PTM-dependent co-activator recruitment","pmids":["11713256"],"is_preprint":false},{"year":2000,"finding":"ERK directly phosphorylates TTF-1 at three serine residues (identified by in vitro kinase assay and alanine mutagenesis), and the Ras/Raf/MEK/ERK pathway represses TTF-1 transcriptional activity; an additional ERK-independent Ras pathway (via V12N38 Ras) cooperates to produce near-complete loss of TTF-1 function.","method":"In vitro kinase assay, site-directed mutagenesis (Ser→Ala), MEK inhibitors (U0126/PD98059), transient transfection reporter assay, Ras effector-region mutants","journal":"Molecular and cellular biology","confidence":"High","confidence_rationale":"Tier 1 — in vitro phosphorylation reconstituted and confirmed by mutagenesis, plus pharmacological epistasis","pmids":["10733581"],"is_preprint":false},{"year":2006,"finding":"PARP-2 (and PARP-1/Ku70/Ku80) co-immunoprecipitate with endogenous TTF-1 in lung epithelial cells; the E domain of PARP-2 interacts with the C-terminal domain of TTF-1; PARP-1 and PARP-2 selectively enhance surfactant protein-B (SP-B) promoter activity when co-expressed with TTF-1.","method":"Co-immunoprecipitation from MLE15 cell extracts, mass spectrometry identification, GST domain-mapping pull-down, transient transfection reporter assay","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 2 — reciprocal Co-IP with MS identification plus domain mapping and functional reporter","pmids":["16461352"],"is_preprint":false},{"year":1998,"finding":"RET/PTC1 oncogene expression leaves TTF-1 protein levels unchanged but renders TTF-1 transcriptionally inactive (assayed on a synthetic TTF-1-target promoter), indicating posttranslational inactivation of TTF-1 function downstream of RET/PTC1 signaling.","method":"Transient transfection reporter assay using synthetic TTF-1 target promoter, Western blot, adoptive overexpression","journal":"Cell growth & differentiation","confidence":"Medium","confidence_rationale":"Tier 2 — clean loss-of-function/gain-of-function with reporter, single lab","pmids":["9438393"],"is_preprint":false},{"year":2004,"finding":"TTF-1 binds to a specific site in the RET promoter; HSCR-associated RET promoter SNPs that overlap the TTF-1 binding site decrease TTF-1-activated RET transcription; a patient-derived TTF-1 missense mutation (Gly322Ser) compromises transactivation of HSCR-associated RET promoter haplotypes.","method":"Luciferase reporter assay, electrophoretic mobility shift assay (EMSA), weighted logistic regression on SNP data, functional mutation analysis","journal":"Human molecular genetics","confidence":"High","confidence_rationale":"Tier 1-2 — EMSA demonstrating direct binding plus functional reporter assay plus patient mutation, multiple methods","pmids":["15548547"],"is_preprint":false},{"year":2001,"finding":"TTF-1 binds to and transactivates the erbB-2 and LHRH gene promoters in hypothalamic neurons, while repressing transcription of the preproenkephalin gene; hypothalamic TTF-1 expression increases transiently prior to puberty onset, suggesting a role in the transcriptional control of female sexual development.","method":"Electrophoretic mobility shift assay (DNA binding), promoter-reporter transactivation assay, intracerebroventricular antisense oligonucleotide knockdown, in situ hybridization, immunohistochemistry","journal":"Molecular and cellular neurosciences","confidence":"High","confidence_rationale":"Tier 1-2 — EMSA plus reporter plus in vivo antisense KD with phenotypic readout, multiple orthogonal methods","pmids":["11161473"],"is_preprint":false},{"year":2006,"finding":"Neuron-specific deletion of Ttf1 in mice causes delayed puberty, reduced reproductive capacity, and a short reproductive span without basal ganglia/hypothalamic morphological defects, demonstrating a post-morphogenic role of TTF-1 in hypothalamic neuroendocrine control of female reproduction.","method":"Conditional neuron-specific Ttf1 knockout mice, gene expression profiling, behavioral/reproductive phenotyping","journal":"The Journal of neuroscience","confidence":"High","confidence_rationale":"Tier 2 — clean conditional KO with defined reproductive phenotype and gene-expression mechanistic follow-up","pmids":["17182767"],"is_preprint":false},{"year":2002,"finding":"TTF-1 activates PACAP gene transcription by binding to six of seven conserved TTF-1-binding motifs in the PACAP 5'-flanking region; deletion of the core motif at -369 abolishes transactivation; intracerebroventricular antisense TTF-1 oligonucleotide knockdown significantly decreases hypothalamic PACAP mRNA.","method":"EMSA (TTF-1 homeodomain binding to PACAP promoter sites), promoter-reporter deletion/mutational analysis, intracerebroventricular antisense KD with RNase protection assay","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 1-2 — EMSA plus deletion reporter plus in vivo antisense KD, multiple orthogonal methods","pmids":["12122016"],"is_preprint":false},{"year":2011,"finding":"MYBPH is a transcriptional target of TTF-1; TTF-1 drives MYBPH expression and MYBPH inhibits ROCK1 through direct physical interaction, thereby suppressing myosin regulatory light chain phosphorylation and LIMK activation, reducing actomyosin-driven single-cell motility and cancer metastasis.","method":"Chromatin immunoprecipitation (TTF-1 on MYBPH promoter), co-immunoprecipitation (MYBPH–ROCK1), in vitro kinase assays, shRNA knockdown, cell motility assays, mouse metastasis models","journal":"The EMBO journal","confidence":"High","confidence_rationale":"Tier 1-2 — ChIP plus reciprocal Co-IP plus kinase assay plus in vivo model, multiple orthogonal methods","pmids":["22085929"],"is_preprint":false},{"year":1994,"finding":"The isolated TTF-1 homeodomain (TTF-1HD) binds DNA as a monomer; its conformational stability is low (Tm 42°C, ΔG ~1.4 kcal/mol) and helical flexibility is important for DNA-binding activity, as small reductions in α-helical content significantly diminish DNA binding.","method":"Circular dichroism thermal denaturation, isothermal urea unfolding, DNA-binding assays","journal":"FEBS letters","confidence":"High","confidence_rationale":"Tier 1 — biophysical structural characterization with direct correlation to DNA-binding function","pmids":["7957942"],"is_preprint":false},{"year":1993,"finding":"The TTF-1 homeodomain (TTF-1HD) exists as a monomer in solution and binds DNA as a monomer; at physiological salt conditions, its affinity for specific DNA sequences is at least 1000-fold higher than for non-specific sequences.","method":"Biochemical DNA-binding assays with titration of KCl concentration, gel-shift (EMSA)","journal":"Biochemical and biophysical research communications","confidence":"High","confidence_rationale":"Tier 1 — in vitro reconstitution of specific vs. non-specific DNA binding, quantitative affinity measurements","pmids":["8267599"],"is_preprint":false},{"year":1998,"finding":"The TTF-1/T/EBP gene is autoregulated: the TTF-1 promoter contains ~24 putative TTF-1 binding sites, and co-transfection of a TTF-1 expression vector activates its own promoter reporter in HepG2 cells that lack endogenous TTF-1; multiple promoters and alternative splicing generate a family of TTF-1 mRNAs.","method":"Cotransfection reporter assay, RNase protection assay, Northern blot, cDNA cloning/sequencing","journal":"Endocrinology","confidence":"Medium","confidence_rationale":"Tier 2 — reporter assay plus molecular characterization, single lab","pmids":["9528987"],"is_preprint":false},{"year":2009,"finding":"Three TTF-1/NKX2-1 missense mutations (L176V, P202L, Q210P) cause loss of transactivation capacity on the human thyroglobulin enhancer/promoter; deficient activity of P202L is completely rescued by cotransfected wild-type PAX8, whereas L176V and Q210P abolish the PAX8 synergism.","method":"Transient transfection transactivation assay on thyroglobulin enhancer/promoter reporter, cotransfection with PAX8","journal":"Human molecular genetics","confidence":"High","confidence_rationale":"Tier 2 — functional mutagenesis with epistatic PAX8 rescue, multiple patient mutations tested","pmids":["19336474"],"is_preprint":false},{"year":1995,"finding":"Antisense oligonucleotide-mediated blockade of TTF-1 in FRTL-5 thyroid cells reduces TSH- and IGF-I-stimulated cell proliferation (DNA synthesis and cell counting) by ~65%, demonstrating that TTF-1 expression is required for thyroid cell proliferation via the cAMP pathway.","method":"Antisense oligonucleotide treatment, DNA synthesis assay, cell counting","journal":"The Journal of biological chemistry","confidence":"Medium","confidence_rationale":"Tier 2 — loss-of-function with defined cellular phenotype, single lab","pmids":["7559458"],"is_preprint":false},{"year":2011,"finding":"TTF-1 transactivates the α5 nicotinic acetylcholine receptor (nAChR) subunit promoter by binding specific TTF-1 response elements; site-directed mutagenesis of these elements abolishes TTF-1-driven α5 transcription in proximal and distal lung epithelial cell lines.","method":"Promoter-reporter assay, site-directed mutagenesis of TTF-1 response elements, exogenous TTF-1 overexpression","journal":"Respiratory research","confidence":"Medium","confidence_rationale":"Tier 2 — mutagenesis of binding sites plus gain-of-function, single lab","pmids":["21143907"],"is_preprint":false},{"year":2008,"finding":"In the TTF-1 proximal promoter, ZBP-89, Sp1/Sp3, and TTF-1 itself bind functional sites identified by EMSA and ChIP; TNF-α inhibits TTF-1 gene transcription and promoter activity, suppressing TTF-1 binding to its own promoter while increasing threonine phosphorylation of Sp1, without altering Sp1 or HNF-3 protein levels.","method":"Promoter deletion analysis, EMSA, chromatin immunoprecipitation (ChIP), mutational analysis, TNF-α treatment of H441 and primary alveolar type II cells","journal":"American journal of physiology. Lung cellular and molecular physiology","confidence":"High","confidence_rationale":"Tier 1-2 — ChIP plus EMSA plus mutagenesis plus cytokine perturbation, multiple orthogonal methods","pmids":["21784970"],"is_preprint":false},{"year":2011,"finding":"TTF-1 inhibits COX-2 gene transcription in hypothalamic astrocytes and endothelial cells by binding to specific sites in the COX-2 promoter; intracerebroventricular antisense TTF-1 knockdown increases COX-2 synthesis in non-neuronal hypothalamic cells and causes hyperthermia.","method":"EMSA (TTF-1 binding to COX-2 promoter sites), promoter-reporter assay, intracerebroventricular antisense oligonucleotide knockdown, double immunohistochemistry, body temperature measurement","journal":"PloS one","confidence":"High","confidence_rationale":"Tier 1-2 — EMSA plus reporter plus in vivo antisense KD with thermoregulatory phenotype","pmids":["22174936"],"is_preprint":false},{"year":2014,"finding":"TTF-1 and its co-regulators FoxA2 and Gata-6 transcriptionally activate the Claudin-6 (Cldn6) promoter in both proximal airway (Beas2B) and distal alveolar (A-549) epithelial cell lines, demonstrating that Cldn6 is a direct transcriptional target of TTF-1 during lung organogenesis.","method":"Promoter-reporter assay (0.5, 1.0, 2.0-kb Cldn6 promoter fragments co-transfected with TTF-1 expression vectors), immunofluorescence co-localization","journal":"Respiratory research","confidence":"Medium","confidence_rationale":"Tier 2 — reporter assay with multiple promoter lengths, single lab","pmids":["24970044"],"is_preprint":false},{"year":2008,"finding":"The TTF-1 response element (TBE at -171 bp) in the hSP-A2 promoter is essential for lung cell-specific, developmental, and hormonal (cAMP/IL-1/dexamethasone) regulation of SP-A2 expression in vivo, demonstrated in transgenic mice where TBE mutation abolishes detectable transgene expression and hormonal responsiveness in fetal lung.","method":"Transgenic mouse reporter assay (hSP-A2-hGH reporter with wild-type or TBE-mutant promoters), cultured fetal lung explant hormone treatment","journal":"American journal of physiology. Lung cellular and molecular physiology","confidence":"High","confidence_rationale":"Tier 1-2 — in vivo transgenic promoter mutagenesis with multiple hormonal readouts","pmids":["18487360"],"is_preprint":false},{"year":2013,"finding":"BRN2, a neural lineage-specific homeoprotein, directly binds the TTF-1 isoform 2 promoter (confirmed by ChIP) and substantially upregulates TTF-1 expression in small-cell lung cancer (SCLC) cells; BRN2 knockdown considerably downregulates TTF-1 in SCLC, whereas FOXA1/2 weakly activate the TTF-1 promoter.","method":"TTF-1 promoter reporter assay, chromatin immunoprecipitation (ChIP), siRNA knockdown of BRN2, transfection of expression vectors (BRN2, FOXA1/2, LHX2/6)","journal":"Laboratory investigation","confidence":"High","confidence_rationale":"Tier 1-2 — ChIP confirming direct binding plus functional reporter plus loss-of-function KD","pmids":["23358112"],"is_preprint":false},{"year":2014,"finding":"mTOR inhibition promotes TTF-1-dependent redifferentiation of thyroid carcinoma cells: siRNA knockdown of TTF-1 completely abrogates mTOR inhibitor-induced sodium-iodide symporter (NIS) expression and increased iodine uptake, placing TTF-1 as a required transcriptional mediator of mTOR-controlled thyroid redifferentiation.","method":"mTOR inhibitor treatment of thyroid carcinoma cell lines (BC-PAP, FTC133, TPC1), siRNA knockdown of TTF-1, NIS mRNA/protein assay, iodine uptake assay","journal":"The Journal of clinical endocrinology and metabolism","confidence":"High","confidence_rationale":"Tier 2 — siRNA epistasis (TTF-1 KD abrogates NIS induction) with functional iodine uptake readout","pmids":["24712572"],"is_preprint":false},{"year":2011,"finding":"Defective nuclear targeting of TTF-1 protein (TTF-1 retained in cytoplasm of type II cells rather than nucleus) is associated with markedly reduced surfactant protein-B synthesis and disrupted surfactant homeostasis in an infant with recurrent respiratory failure, functionally linking TTF-1 nuclear localization to SP-B transcription.","method":"Confocal immunofluorescence microscopy of lung biopsy, SP-B kinetic stable-isotope synthesis assay, ABCA3/SFTPB/NKX2.1 gene sequencing","journal":"Respiratory research","confidence":"Medium","confidence_rationale":"Tier 2 — direct localization experiment tied to functional surfactant phenotype, single clinical case with mechanistic follow-up","pmids":["21867529"],"is_preprint":false}],"current_model":"TTF-1 (NKX2-1) is a homeodomain transcription factor that binds specific DNA motifs as a monomer to directly activate lung surfactant protein genes (SP-A, SP-B, SP-C) and thyroid-specific genes (thyroglobulin, thyroperoxidase, NIS), with its transcriptional activity modulated by PKA phosphorylation, acetylation by CBP/p300, recruitment of co-activators SRC-1, TAZ, and PARP-2, and repression by ERK-mediated phosphorylation downstream of Ras/Raf signaling; nuclear localization of TTF-1 is required for surfactant homeostasis, and in the hypothalamus TTF-1 activates LHRH, erbB-2, and PACAP promoters while repressing preproenkephalin and COX-2, thereby controlling female sexual development and neuroendocrine function."},"narrative":{"teleology":[{"year":1991,"claim":"Establishing TTF-1 as a tissue-restricted transcription factor: prior to this work, the gene targets and expression domains of TTF-1 were unknown; this study showed it activates thyroglobulin and thyroperoxidase promoters and is expressed in thyroid, lung, and select brain regions from the earliest stages of organogenesis.","evidence":"In situ hybridization, immunohistochemistry, and promoter-reporter assays in thyroid cell lines","pmids":["1811929"],"confidence":"High","gaps":["Lung and brain target genes not yet identified","No loss-of-function evidence for developmental necessity"]},{"year":1993,"claim":"Resolving TTF-1's DNA-binding mode: it was unclear whether TTF-1 bound DNA as a dimer like many homeodomain proteins; biophysical analysis demonstrated monomeric binding with ≥1000-fold specificity over non-specific DNA, and later work showed the homeodomain's low conformational stability is critical for binding activity.","evidence":"Quantitative EMSA with salt titration (1993); circular dichroism thermal denaturation and urea unfolding coupled to DNA-binding assays (1994)","pmids":["8267599","7957942"],"confidence":"High","gaps":["No high-resolution structure of full-length TTF-1 on DNA","Contribution of flanking domains to specificity unexplored"]},{"year":1995,"claim":"Demonstrating a proliferative requirement: TTF-1 had been characterized only as a differentiation factor; antisense knockdown revealed it is also required for TSH- and IGF-I-stimulated thyroid cell proliferation, broadening its role beyond terminal differentiation.","evidence":"Antisense oligonucleotide treatment of FRTL-5 thyroid cells with DNA synthesis and cell counting assays","pmids":["7559458"],"confidence":"Medium","gaps":["Antisense approach lacks specificity controls of modern RNAi/knockout","Downstream proliferative targets not identified"]},{"year":1998,"claim":"Identifying oncogene-mediated post-translational repression and autoregulation: it was unknown how oncogenic signaling affects TTF-1; RET/PTC1 was shown to inactivate TTF-1 without reducing its protein level, and separately, TTF-1 was found to positively autoregulate its own promoter.","evidence":"Reporter assays with RET/PTC1 overexpression (1998); TTF-1 co-transfection activating its own promoter in HepG2 cells (1998)","pmids":["9438393","9528987"],"confidence":"Medium","gaps":["Mechanism of RET/PTC1-mediated inactivation not resolved at phosphorylation/PTM level","Autoregulation not confirmed by ChIP in endogenous context"]},{"year":2000,"claim":"Mapping the ERK phosphorylation sites that repress TTF-1: the post-translational mechanism by which Ras signaling inhibits TTF-1 was unknown; ERK was shown to directly phosphorylate three serines on TTF-1, with an additional ERK-independent Ras pathway cooperating for near-complete inactivation.","evidence":"In vitro kinase assay, Ser→Ala mutagenesis, MEK inhibitors, and Ras effector-domain mutants in reporter assays","pmids":["10733581"],"confidence":"High","gaps":["Identity of the ERK-independent Ras effector pathway not resolved","In vivo phosphorylation stoichiometry unknown"]},{"year":2001,"claim":"Defining the co-activator complex and PKA-dependent acetylation switch: it was unclear how cAMP/PKA signaling enhances TTF-1 activity; CBP/p300 and SRC-1 were shown to interact with TTF-1 in lung type II cells, with PKA phosphorylation promoting this interaction and TTF-1 hyperacetylation, thereby boosting SP-A transactivation.","evidence":"GST pull-down, immunodepletion, PKA overexpression, adenoviral E1A competition, and cAMP-induced acetylation assays","pmids":["11713256"],"confidence":"High","gaps":["Specific acetylation sites on TTF-1 not mapped","Relative contributions of SRC-1 vs. CBP/p300 not dissected in vivo"]},{"year":2001,"claim":"Extending TTF-1 into neuroendocrine gene regulation: it was unknown whether TTF-1 controlled hypothalamic genes; TTF-1 was shown to activate LHRH and erbB-2 promoters and repress preproenkephalin in hypothalamic neurons, with expression peaking before puberty.","evidence":"EMSA, promoter-reporter assays, intracerebroventricular antisense knockdown, ISH, and IHC in rat hypothalamus","pmids":["11161473"],"confidence":"High","gaps":["Direct chromatin occupancy at hypothalamic targets not shown (no ChIP)","Mechanism of transcriptional repression not characterized"]},{"year":2002,"claim":"Identifying PACAP as a direct TTF-1 target in the hypothalamus: this connected TTF-1 to neuropeptide circuits beyond LHRH, showing binding to six motifs in the PACAP promoter and demonstrating in vivo dependence of PACAP mRNA on TTF-1.","evidence":"EMSA, promoter deletion/mutation reporter analysis, intracerebroventricular antisense knockdown with RNase protection assay","pmids":["12122016"],"confidence":"High","gaps":["No ChIP confirmation of occupancy in vivo","Functional consequence of PACAP reduction on puberty not tested"]},{"year":2004,"claim":"Recruiting TAZ as a co-activator for lung surfactant gene activation and linking TTF-1 to RET in Hirschsprung disease: TAZ was shown to synergize with TTF-1 on the SP-C promoter via WW domain–N-terminal interaction; separately, TTF-1 was found to directly bind the RET promoter, with HSCR-associated SNPs and a patient TTF-1 mutation compromising this activation.","evidence":"Mammalian two-hybrid, GST pull-down, deletion mapping, reporter assays (TAZ study); EMSA, reporter assay, logistic regression on HSCR SNPs (RET study)","pmids":["14970209","15548547"],"confidence":"High","gaps":["TAZ interaction not validated by endogenous Co-IP","Functional impact of RET promoter regulation on enteric nervous system development not shown in animal model"]},{"year":2006,"claim":"Identifying PARP-1/PARP-2 as endogenous TTF-1 partners that selectively enhance SP-B: the co-activator landscape for SP-B was undefined; PARP-2 was found to interact with TTF-1's C-terminal domain and specifically boost SP-B promoter activity, together with PARP-1 and Ku70/Ku80 identified by mass spectrometry.","evidence":"Co-immunoprecipitation from MLE15 cells, mass spectrometry, GST domain mapping, reporter assay","pmids":["16461352"],"confidence":"High","gaps":["Whether PARP enzymatic activity (PARylation) is required for co-activation not tested","In vivo relevance in PARP-2 knockout lungs not assessed"]},{"year":2006,"claim":"Establishing an in vivo post-morphogenic role of TTF-1 in female reproduction: conditional neuron-specific Ttf1 knockout mice showed delayed puberty and shortened reproductive lifespan without hypothalamic structural defects, proving TTF-1 acts beyond early brain patterning.","evidence":"Conditional neuron-specific Ttf1 knockout mice with reproductive phenotyping and gene expression profiling","pmids":["17182767"],"confidence":"High","gaps":["Specific neuronal subtypes requiring TTF-1 not resolved","Direct targets mediating the reproductive phenotype not fully identified"]},{"year":2008,"claim":"Demonstrating that the TTF-1 binding element is essential for in vivo lung-specific and hormonally regulated SP-A2 expression: transgenic mice with a mutated TBE showed complete loss of SP-A2 transgene expression and hormonal responsiveness, confirming TTF-1 as a non-redundant in vivo driver of surfactant gene regulation.","evidence":"Transgenic mouse reporter with wild-type vs. TBE-mutant hSP-A2 promoters, fetal lung explant hormone treatment","pmids":["18487360"],"confidence":"High","gaps":["Whether other TTF-1 sites compensate for TBE loss at endogenous locus not tested","Chromatin accessibility changes at mutant TBE not examined"]},{"year":2011,"claim":"Expanding TTF-1's role to anti-metastatic transcriptional programs and hypothalamic thermoregulation: TTF-1 was shown to directly activate MYBPH transcription (suppressing ROCK1-driven cell motility and metastasis) and to repress COX-2 in hypothalamic non-neuronal cells (controlling body temperature).","evidence":"ChIP on MYBPH promoter, MYBPH–ROCK1 Co-IP, kinase assays, mouse metastasis model (MYBPH study); EMSA, reporter, in vivo antisense KD with temperature measurement (COX-2 study)","pmids":["22085929","22174936"],"confidence":"High","gaps":["MYBPH-independent anti-metastatic targets of TTF-1 not delineated","Molecular mechanism of COX-2 repression (co-repressor identity) not defined"]},{"year":2011,"claim":"Linking TTF-1 nuclear localization directly to surfactant homeostasis in human disease: cytoplasmic retention of TTF-1 protein in type II pneumocytes was associated with markedly reduced SP-B synthesis and respiratory failure in an infant, functionally connecting nuclear import to transcriptional output.","evidence":"Confocal immunofluorescence of lung biopsy, stable-isotope SP-B kinetic assay, gene sequencing","pmids":["21867529"],"confidence":"Medium","gaps":["Mechanism causing cytoplasmic retention not identified","Single clinical case without genetic rescue or cell-based validation","Causative mutation or transport defect not established"]},{"year":2014,"claim":"Positioning TTF-1 as the required mediator of mTOR inhibitor-induced thyroid redifferentiation: siRNA knockdown of TTF-1 completely abolished NIS re-expression and iodine uptake induced by mTOR inhibition, establishing TTF-1 downstream of mTOR signaling in thyroid cancer cells.","evidence":"mTOR inhibitor treatment of thyroid carcinoma lines, TTF-1 siRNA epistasis, NIS mRNA/protein and iodine uptake assays","pmids":["24712572"],"confidence":"High","gaps":["Whether mTOR controls TTF-1 protein stability, phosphorylation, or transcription not resolved","In vivo relevance for radioiodine therapy not demonstrated"]},{"year":null,"claim":"Unresolved: the full genome-wide target repertoire of TTF-1 across its three expression domains (thyroid, lung, brain) has not been systematically defined by ChIP-seq; the structural basis for how post-translational modifications alter TTF-1 conformation and co-activator selectivity remains unknown; and the nuclear import mechanism whose failure causes surfactant disease has not been identified.","evidence":"","pmids":[],"confidence":"Low","gaps":["No genome-wide ChIP-seq across tissue types","No full-length TTF-1 crystal or cryo-EM structure","Nuclear import pathway and transport signals not characterized"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0003677","term_label":"DNA binding","supporting_discovery_ids":[0,6,7,9,10,11,12,17,18,20]},{"term_id":"GO:0140110","term_label":"transcription regulator activity","supporting_discovery_ids":[0,1,2,6,7,9,10,14,16,18,19,20,22]}],"localization":[{"term_id":"GO:0005634","term_label":"nucleus","supporting_discovery_ids":[0,23]}],"pathway":[{"term_id":"R-HSA-74160","term_label":"Gene expression (Transcription)","supporting_discovery_ids":[0,1,2,6,7,9,10,14,16,18,19,20,22]},{"term_id":"R-HSA-162582","term_label":"Signal Transduction","supporting_discovery_ids":[3,5,22]},{"term_id":"R-HSA-1266738","term_label":"Developmental Biology","supporting_discovery_ids":[0,8,19]}],"complexes":[],"partners":["CBP","SRC1","TAZ","PARP1","PARP2","PAX8","BRN2","FOXA2"],"other_free_text":[]},"mechanistic_narrative":"TTF-1 (NKX2-1) is a homeodomain transcription factor that serves as a master regulator of tissue-specific gene expression in the thyroid, lung, and hypothalamus, coordinating differentiation, surfactant homeostasis, neuroendocrine function, and cell proliferation. It binds DNA as a monomer with high sequence specificity and activates thyroglobulin, thyroperoxidase, surfactant protein (SP-A, SP-B, SP-C), RET, PACAP, LHRH, erbB-2, Claudin-6, MYBPH, and α5 nAChR promoters while repressing preproenkephalin and COX-2 transcription [PMID:1811929, PMID:12122016, PMID:11161473, PMID:22174936, PMID:22085929, PMID:15548547]. Its transcriptional output is positively regulated by PKA-dependent phosphorylation and acetylation via CBP/p300 and SRC-1, and by co-activators TAZ and PARP-1/PARP-2, whereas ERK-mediated phosphorylation downstream of Ras/Raf signaling and RET/PTC1 oncogene activity repress TTF-1 function post-translationally [PMID:11713256, PMID:14970209, PMID:16461352, PMID:10733581, PMID:9438393]. Neuron-specific deletion in mice causes delayed puberty and reduced reproductive capacity without gross morphological defects, establishing a post-morphogenic role in hypothalamic control of female reproduction [PMID:17182767]."},"prefetch_data":{"uniprot":{"accession":"Q15361","full_name":"Transcription termination factor 1","aliases":["RNA polymerase I termination factor","Transcription termination factor I","TTF-I"],"length_aa":905,"mass_kda":103.1,"function":"Multifunctional nucleolar protein that terminates ribosomal gene transcription, mediates replication fork arrest and regulates RNA polymerase I transcription on chromatin. Plays a dual role in rDNA regulation, being involved in both activation and silencing of rDNA transcription. Interaction with BAZ2A/TIP5 recovers DNA-binding activity","subcellular_location":"Nucleus; Nucleus, nucleolus; Nucleus, nucleoplasm","url":"https://www.uniprot.org/uniprotkb/Q15361/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":true,"resolved_as":"","url":"https://depmap.org/portal/gene/TTF1","classification":"Common Essential","n_dependent_lines":527,"n_total_lines":1208,"dependency_fraction":0.43625827814569534},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[],"url":"https://opencell.sf.czbiohub.org/search/TTF1","total_profiled":1310},"omim":[{"mim_id":"619280","title":"COILED-COIL DOMAIN-CONTAINING PROTEIN 59; CCDC59","url":"https://www.omim.org/entry/619280"},{"mim_id":"610978","title":"CHOREOATHETOSIS AND CONGENITAL HYPOTHYROIDISM WITH OR WITHOUT PULMONARY DYSFUNCTION; CAHTP","url":"https://www.omim.org/entry/610978"},{"mim_id":"609413","title":"ERCC EXCISION REPAIR 6, CHROMATIN REMODELING FACTOR; ERCC6","url":"https://www.omim.org/entry/609413"},{"mim_id":"608144","title":"SAM POINTED DOMAIN-CONTAINING ETS TRANSCRIPTION FACTOR; SPDEF","url":"https://www.omim.org/entry/608144"},{"mim_id":"607808","title":"NK2 HOMEOBOX 4; NKX2-4","url":"https://www.omim.org/entry/607808"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Supported","locations":[{"location":"Nucleoli fibrillar center","reliability":"Supported"}],"tissue_specificity":"Low tissue specificity","tissue_distribution":"Detected in all","driving_tissues":[],"url":"https://www.proteinatlas.org/search/TTF1"},"hgnc":{"alias_symbol":[],"prev_symbol":[]},"alphafold":{"accession":"Q15361","domains":[{"cath_id":"1.10.10.60","chopping":"614-661","consensus_level":"medium","plddt":89.54,"start":614,"end":661},{"cath_id":"-","chopping":"664-749_855-871","consensus_level":"medium","plddt":79.7471,"start":664,"end":871},{"cath_id":"-","chopping":"756-852","consensus_level":"medium","plddt":85.8454,"start":756,"end":852}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q15361","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q15361-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q15361-F1-predicted_aligned_error_v6.png","plddt_mean":57.12},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=TTF1","jax_strain_url":"https://www.jax.org/strain/search?query=TTF1"},"sequence":{"accession":"Q15361","fasta_url":"https://rest.uniprot.org/uniprotkb/Q15361.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q15361/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q15361"}},"corpus_meta":[{"pmid":"1811929","id":"PMC_1811929","title":"The transcription factor TTF-1 is expressed at the onset of thyroid and lung morphogenesis and in restricted regions of the foetal brain.","date":"1991","source":"Development (Cambridge, England)","url":"https://pubmed.ncbi.nlm.nih.gov/1811929","citation_count":788,"is_preprint":false},{"pmid":"12023581","id":"PMC_12023581","title":"TTF-1 expression in pulmonary adenocarcinomas.","date":"2002","source":"The American journal of surgical pathology","url":"https://pubmed.ncbi.nlm.nih.gov/12023581","citation_count":296,"is_preprint":false},{"pmid":"8062273","id":"PMC_8062273","title":"Expression of thyroid-specific transcription factors TTF-1 and PAX-8 in human thyroid neoplasms.","date":"1994","source":"Cancer research","url":"https://pubmed.ncbi.nlm.nih.gov/8062273","citation_count":222,"is_preprint":false},{"pmid":"14970209","id":"PMC_14970209","title":"TAZ interacts with TTF-1 and regulates expression of surfactant protein-C.","date":"2004","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/14970209","citation_count":150,"is_preprint":false},{"pmid":"19336474","id":"PMC_19336474","title":"Five new TTF1/NKX2.1 mutations in brain-lung-thyroid syndrome: rescue by PAX8 synergism in one case.","date":"2009","source":"Human molecular genetics","url":"https://pubmed.ncbi.nlm.nih.gov/19336474","citation_count":150,"is_preprint":false},{"pmid":"12760288","id":"PMC_12760288","title":"p63 and TTF-1 immunostaining. A useful marker panel for distinguishing small cell carcinoma of lung from poorly differentiated squamous cell carcinoma of lung.","date":"2003","source":"American journal of clinical pathology","url":"https://pubmed.ncbi.nlm.nih.gov/12760288","citation_count":122,"is_preprint":false},{"pmid":"28555282","id":"PMC_28555282","title":"SMARCA4-deficient pulmonary adenocarcinoma: clinicopathological, immunohistochemical, and molecular characteristics of a novel aggressive neoplasm with a consistent TTF1neg/CK7pos/HepPar-1pos immunophenotype.","date":"2017","source":"Virchows Archiv : an international journal of pathology","url":"https://pubmed.ncbi.nlm.nih.gov/28555282","citation_count":116,"is_preprint":false},{"pmid":"15188024","id":"PMC_15188024","title":"The role of TTF-1 in differentiating primary and metastatic lung adenocarcinomas.","date":"2004","source":"Pathology oncology research : POR","url":"https://pubmed.ncbi.nlm.nih.gov/15188024","citation_count":98,"is_preprint":false},{"pmid":"20182342","id":"PMC_20182342","title":"An immunohistochemical study of cervical neuroendocrine carcinomas: Neoplasms that are commonly TTF1 positive and which may express CK20 and P63.","date":"2010","source":"The American journal of surgical pathology","url":"https://pubmed.ncbi.nlm.nih.gov/20182342","citation_count":98,"is_preprint":false},{"pmid":"11161473","id":"PMC_11161473","title":"TTF-1, a homeodomain gene required for diencephalic morphogenesis, is postnatally expressed in the neuroendocrine brain in a developmentally regulated and cell-specific fashion.","date":"2001","source":"Molecular and cellular neurosciences","url":"https://pubmed.ncbi.nlm.nih.gov/11161473","citation_count":97,"is_preprint":false},{"pmid":"21464700","id":"PMC_21464700","title":"Combination of napsin A and TTF-1 immunohistochemistry helps in differentiating primary lung adenocarcinoma from metastatic carcinoma in the lung.","date":"2011","source":"Applied immunohistochemistry & molecular morphology : AIMM","url":"https://pubmed.ncbi.nlm.nih.gov/21464700","citation_count":96,"is_preprint":false},{"pmid":"15716236","id":"PMC_15716236","title":"Usefulness of CDX2 and TTF-1 in differentiating gastrointestinal from pulmonary carcinoids.","date":"2005","source":"American journal of clinical pathology","url":"https://pubmed.ncbi.nlm.nih.gov/15716236","citation_count":87,"is_preprint":false},{"pmid":"15976812","id":"PMC_15976812","title":"Alternative epithelial markers in sarcomatoid carcinomas of the head and neck, lung, and bladder-p63, MOC-31, and TTF-1.","date":"2005","source":"Modern pathology : an official journal of the United States and Canadian Academy of Pathology, Inc","url":"https://pubmed.ncbi.nlm.nih.gov/15976812","citation_count":86,"is_preprint":false},{"pmid":"10746684","id":"PMC_10746684","title":"Expression of thyroid transcription factor-1 (TTF-1) in human C cells and medullary thyroid carcinomas.","date":"2000","source":"Human pathology","url":"https://pubmed.ncbi.nlm.nih.gov/10746684","citation_count":75,"is_preprint":false},{"pmid":"22085929","id":"PMC_22085929","title":"MYBPH, a transcriptional target of TTF-1, inhibits ROCK1, and reduces cell motility and metastasis.","date":"2011","source":"The EMBO journal","url":"https://pubmed.ncbi.nlm.nih.gov/22085929","citation_count":74,"is_preprint":false},{"pmid":"15548547","id":"PMC_15548547","title":"TTF-1 and RET promoter SNPs: regulation of RET transcription in Hirschsprung's disease.","date":"2004","source":"Human molecular genetics","url":"https://pubmed.ncbi.nlm.nih.gov/15548547","citation_count":74,"is_preprint":false},{"pmid":"22498824","id":"PMC_22498824","title":"PDX-1, CDX-2, TTF-1, and CK7: a reliable immunohistochemical panel for pancreatic neuroendocrine neoplasms.","date":"2012","source":"The American journal of surgical pathology","url":"https://pubmed.ncbi.nlm.nih.gov/22498824","citation_count":72,"is_preprint":false},{"pmid":"16680154","id":"PMC_16680154","title":"TTF-1 and p63 for distinguishing pulmonary small-cell carcinoma from poorly differentiated squamous cell carcinoma in previously pap-stained cytologic material.","date":"2006","source":"Modern pathology : an official journal of the United States and Canadian Academy of Pathology, Inc","url":"https://pubmed.ncbi.nlm.nih.gov/16680154","citation_count":72,"is_preprint":false},{"pmid":"15494931","id":"PMC_15494931","title":"Histopathologic classification of lung cancer: Relevance of cytokeratin and TTF-1 immunophenotyping.","date":"2004","source":"Annals of diagnostic pathology","url":"https://pubmed.ncbi.nlm.nih.gov/15494931","citation_count":67,"is_preprint":false},{"pmid":"11713256","id":"PMC_11713256","title":"Role of CBP/p300 and SRC-1 in transcriptional regulation of the pulmonary surfactant protein-A (SP-A) gene by thyroid transcription factor-1 (TTF-1).","date":"2001","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/11713256","citation_count":67,"is_preprint":false},{"pmid":"23787483","id":"PMC_23787483","title":"A mutation in TTF1/NKX2.1 is associated with familial neuroendocrine cell hyperplasia of infancy.","date":"2013","source":"Chest","url":"https://pubmed.ncbi.nlm.nih.gov/23787483","citation_count":65,"is_preprint":false},{"pmid":"21287692","id":"PMC_21287692","title":"TTF-1 and Napsin A double stain: a useful marker for diagnosing lung adenocarcinoma on fine-needle aspiration cell blocks.","date":"2011","source":"Cancer cytopathology","url":"https://pubmed.ncbi.nlm.nih.gov/21287692","citation_count":65,"is_preprint":false},{"pmid":"25878335","id":"PMC_25878335","title":"An Integrated Molecular Analysis of Lung Adenocarcinomas Identifies Potential Therapeutic Targets among TTF1-Negative Tumors, Including DNA Repair Proteins and Nrf2.","date":"2015","source":"Clinical cancer research : an official journal of the American Association for Cancer Research","url":"https://pubmed.ncbi.nlm.nih.gov/25878335","citation_count":56,"is_preprint":false},{"pmid":"24746197","id":"PMC_24746197","title":"The utility of a novel triple marker (combination of TTF1, napsin A, and p40) in the subclassification of non-small cell lung cancer.","date":"2014","source":"Human pathology","url":"https://pubmed.ncbi.nlm.nih.gov/24746197","citation_count":55,"is_preprint":false},{"pmid":"10733581","id":"PMC_10733581","title":"Multiple ras downstream pathways mediate functional repression of the homeobox gene product TTF-1.","date":"2000","source":"Molecular and cellular biology","url":"https://pubmed.ncbi.nlm.nih.gov/10733581","citation_count":54,"is_preprint":false},{"pmid":"20694477","id":"PMC_20694477","title":"TTF1 expression in normal lung neuroendocrine cells and related tumors: immunohistochemical study comparing two different monoclonal antibodies.","date":"2010","source":"Virchows Archiv : an international journal of pathology","url":"https://pubmed.ncbi.nlm.nih.gov/20694477","citation_count":53,"is_preprint":false},{"pmid":"9438393","id":"PMC_9438393","title":"Expression of the RET/PTC1 oncogene impairs the activity of TTF-1 and Pax-8 thyroid transcription factors.","date":"1998","source":"Cell growth & differentiation : the molecular biology journal of the American Association for Cancer Research","url":"https://pubmed.ncbi.nlm.nih.gov/9438393","citation_count":51,"is_preprint":false},{"pmid":"16461352","id":"PMC_16461352","title":"PARP-2 interacts with TTF-1 and regulates expression of surfactant protein-B.","date":"2006","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/16461352","citation_count":49,"is_preprint":false},{"pmid":"9528987","id":"PMC_9528987","title":"Multiple transcripts encoded by the thyroid-specific enhancer-binding protein (T/EBP)/thyroid-specific transcription factor-1 (TTF-1) gene: evidence of autoregulation.","date":"1998","source":"Endocrinology","url":"https://pubmed.ncbi.nlm.nih.gov/9528987","citation_count":49,"is_preprint":false},{"pmid":"21838611","id":"PMC_21838611","title":"Diagnostic utility of PAX8, TTF-1 and napsin A for discriminating metastatic carcinoma from primary adenocarcinoma of the lung.","date":"2011","source":"Biotechnic & histochemistry : official publication of the Biological Stain Commission","url":"https://pubmed.ncbi.nlm.nih.gov/21838611","citation_count":48,"is_preprint":false},{"pmid":"17182767","id":"PMC_17182767","title":"Deletion of the Ttf1 gene in differentiated neurons disrupts female reproduction without impairing basal ganglia function.","date":"2006","source":"The Journal of neuroscience : the official journal of the Society for Neuroscience","url":"https://pubmed.ncbi.nlm.nih.gov/17182767","citation_count":47,"is_preprint":false},{"pmid":"7559458","id":"PMC_7559458","title":"Function of the homeo and paired domain proteins TTF-1 and Pax-8 in thyroid cell proliferation.","date":"1995","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/7559458","citation_count":47,"is_preprint":false},{"pmid":"11416863","id":"PMC_11416863","title":"Expression of thyroid transcription factor-1 (TTF-1) gene in the ventral forebrain and endostyle of the agnathan vertebrate, Lampetra japonica.","date":"2001","source":"Genesis (New York, N.Y. : 2000)","url":"https://pubmed.ncbi.nlm.nih.gov/11416863","citation_count":47,"is_preprint":false},{"pmid":"9226206","id":"PMC_9226206","title":"Absence of mutations in the gene encoding thyroid transcription factor-1 (TTF-1) in patients with thyroid dysgenesis.","date":"1997","source":"Thyroid : official journal of the American Thyroid Association","url":"https://pubmed.ncbi.nlm.nih.gov/9226206","citation_count":46,"is_preprint":false},{"pmid":"24743427","id":"PMC_24743427","title":"The relationship between TTF-1 expression and EGFR mutations in lung adenocarcinomas.","date":"2014","source":"PloS one","url":"https://pubmed.ncbi.nlm.nih.gov/24743427","citation_count":44,"is_preprint":false},{"pmid":"19279207","id":"PMC_19279207","title":"Characterizing the developmental pathways TTF-1, NKX2-8, and PAX9 in lung cancer.","date":"2009","source":"Proceedings of the National Academy of Sciences of the United States of America","url":"https://pubmed.ncbi.nlm.nih.gov/19279207","citation_count":44,"is_preprint":false},{"pmid":"23701182","id":"PMC_23701182","title":"Update on hypophysitis and TTF-1 expressing sellar region masses.","date":"2013","source":"Brain pathology (Zurich, Switzerland)","url":"https://pubmed.ncbi.nlm.nih.gov/23701182","citation_count":43,"is_preprint":false},{"pmid":"17727473","id":"PMC_17727473","title":"Biomarker-assisted diagnosis of ovarian, cervical and pulmonary small cell carcinomas: the role of TTF-1, WT-1 and HPV analysis.","date":"2007","source":"Histopathology","url":"https://pubmed.ncbi.nlm.nih.gov/17727473","citation_count":43,"is_preprint":false},{"pmid":"18754327","id":"PMC_18754327","title":"If it's not CK5/6 positive, TTF-1 negative it's not a squamous cell carcinoma of lung.","date":"2008","source":"APMIS : acta pathologica, microbiologica, et immunologica Scandinavica","url":"https://pubmed.ncbi.nlm.nih.gov/18754327","citation_count":39,"is_preprint":false},{"pmid":"17497661","id":"PMC_17497661","title":"WT1, monoclonal CEA, TTF1, and CA125 antibodies in the differential diagnosis of lung, breast, and ovarian adenocarcinomas in serous effusions.","date":"2007","source":"Diagnostic cytopathology","url":"https://pubmed.ncbi.nlm.nih.gov/17497661","citation_count":39,"is_preprint":false},{"pmid":"18682709","id":"PMC_18682709","title":"Induction of sodium iodide symporter gene and molecular characterisation of HNF3 beta/FoxA2, TTF-1 and C/EBP beta in thyroid carcinoma cells.","date":"2008","source":"British journal of cancer","url":"https://pubmed.ncbi.nlm.nih.gov/18682709","citation_count":38,"is_preprint":false},{"pmid":"24712572","id":"PMC_24712572","title":"mTOR Inhibition promotes TTF1-dependent redifferentiation and restores iodine uptake in thyroid carcinoma cell lines.","date":"2014","source":"The Journal of clinical endocrinology and metabolism","url":"https://pubmed.ncbi.nlm.nih.gov/24712572","citation_count":37,"is_preprint":false},{"pmid":"19318803","id":"PMC_19318803","title":"Cutaneous metastasis from large-cell neuroendocrine carcinoma of the urinary bladder expressing CK20 and TTF-1.","date":"2009","source":"The American Journal of dermatopathology","url":"https://pubmed.ncbi.nlm.nih.gov/19318803","citation_count":31,"is_preprint":false},{"pmid":"12591604","id":"PMC_12591604","title":"Developmental cooperation of leukemia inhibitory factor and insulin-like growth factor I in mice is tissue-specific and essential for lung maturation involving the transcription factors Sp3 and TTF-1.","date":"2003","source":"Mechanisms of development","url":"https://pubmed.ncbi.nlm.nih.gov/12591604","citation_count":31,"is_preprint":false},{"pmid":"27573549","id":"PMC_27573549","title":"Induction of TTF-1 or PAX-8 expression on proliferation and tumorigenicity in thyroid carcinomas.","date":"2016","source":"International journal of oncology","url":"https://pubmed.ncbi.nlm.nih.gov/27573549","citation_count":30,"is_preprint":false},{"pmid":"19620839","id":"PMC_19620839","title":"GCDFP-15 positive and TTF-1 negative primary lung neoplasms: a tissue microarray study of 381 primary lung tumors.","date":"2009","source":"Applied immunohistochemistry & molecular morphology : AIMM","url":"https://pubmed.ncbi.nlm.nih.gov/19620839","citation_count":28,"is_preprint":false},{"pmid":"23358112","id":"PMC_23358112","title":"Neural lineage-specific homeoprotein BRN2 is directly involved in TTF1 expression in small-cell lung cancer.","date":"2013","source":"Laboratory investigation; a journal of technical methods and pathology","url":"https://pubmed.ncbi.nlm.nih.gov/23358112","citation_count":27,"is_preprint":false},{"pmid":"28349943","id":"PMC_28349943","title":"TTF-1- and/or CD56-positive Circulating Tumor Cells in patients with small cell lung cancer (SCLC).","date":"2017","source":"Scientific reports","url":"https://pubmed.ncbi.nlm.nih.gov/28349943","citation_count":26,"is_preprint":false},{"pmid":"24111789","id":"PMC_24111789","title":"TTF-1 expression in breast carcinoma: an unusual but real phenomenon.","date":"2013","source":"Histopathology","url":"https://pubmed.ncbi.nlm.nih.gov/24111789","citation_count":25,"is_preprint":false},{"pmid":"24970044","id":"PMC_24970044","title":"Developmental lung expression and transcriptional regulation of claudin-6 by TTF-1, Gata-6, and FoxA2.","date":"2014","source":"Respiratory research","url":"https://pubmed.ncbi.nlm.nih.gov/24970044","citation_count":25,"is_preprint":false},{"pmid":"18855882","id":"PMC_18855882","title":"Transcription expression and clinical significance of TTF-1 mRNA in pleural effusion of patients with lung cancer.","date":"2008","source":"Diagnostic cytopathology","url":"https://pubmed.ncbi.nlm.nih.gov/18855882","citation_count":25,"is_preprint":false},{"pmid":"31133441","id":"PMC_31133441","title":"Value of SATB2, ISL1, and TTF1 to differentiate rectal from other gastrointestinal and lung well-differentiated neuroendocrine tumors.","date":"2019","source":"Pathology, research and practice","url":"https://pubmed.ncbi.nlm.nih.gov/31133441","citation_count":23,"is_preprint":false},{"pmid":"28807344","id":"PMC_28807344","title":"Pituicytoma: Review of commonalities and distinguishing features among TTF-1 positive tumors of the central nervous system.","date":"2017","source":"Annals of diagnostic pathology","url":"https://pubmed.ncbi.nlm.nih.gov/28807344","citation_count":23,"is_preprint":false},{"pmid":"7957942","id":"PMC_7957942","title":"Analysis of the conformation and stability of rat TTF-1 homeodomain by circular dichroism.","date":"1994","source":"FEBS letters","url":"https://pubmed.ncbi.nlm.nih.gov/7957942","citation_count":22,"is_preprint":false},{"pmid":"25982999","id":"PMC_25982999","title":"The expression of TTF-1 and Napsin A in early-stage lung adenocarcinoma correlates with the results of surgical treatment.","date":"2015","source":"Tumour biology : the journal of the International Society for Oncodevelopmental Biology and Medicine","url":"https://pubmed.ncbi.nlm.nih.gov/25982999","citation_count":22,"is_preprint":false},{"pmid":"12122016","id":"PMC_12122016","title":"Regulation of pituitary adenylate cyclase-activating polypeptide gene transcription by TTF-1, a homeodomain-containing transcription factor.","date":"2002","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/12122016","citation_count":22,"is_preprint":false},{"pmid":"26427663","id":"PMC_26427663","title":"The diagnostic utility of the triple markers Napsin A, TTF-1, and PAX8 in differentiating between primary and metastatic lung carcinomas.","date":"2015","source":"Tumour biology : the journal of the International Society for Oncodevelopmental Biology and Medicine","url":"https://pubmed.ncbi.nlm.nih.gov/26427663","citation_count":21,"is_preprint":false},{"pmid":"25120805","id":"PMC_25120805","title":"ΔNp63, CK5/6, TTF-1 and napsin A, a reliable panel to subtype non-small cell lung cancer in biopsy specimens.","date":"2014","source":"International journal of clinical and experimental pathology","url":"https://pubmed.ncbi.nlm.nih.gov/25120805","citation_count":20,"is_preprint":false},{"pmid":"19011567","id":"PMC_19011567","title":"TTF-1 expression in nephroblastoma.","date":"2009","source":"The American journal of surgical pathology","url":"https://pubmed.ncbi.nlm.nih.gov/19011567","citation_count":20,"is_preprint":false},{"pmid":"26799356","id":"PMC_26799356","title":"Utility of TTF-1 and Napsin-A in the work-up of malignant effusions.","date":"2016","source":"Diagnostic cytopathology","url":"https://pubmed.ncbi.nlm.nih.gov/26799356","citation_count":20,"is_preprint":false},{"pmid":"21784970","id":"PMC_21784970","title":"Thyroid transcription factor-1 (TTF-1) gene: identification of ZBP-89, Sp1, and TTF-1 sites in the promoter and regulation by TNF-α in lung epithelial cells.","date":"2011","source":"American journal of physiology. Lung cellular and molecular physiology","url":"https://pubmed.ncbi.nlm.nih.gov/21784970","citation_count":20,"is_preprint":false},{"pmid":"36130728","id":"PMC_36130728","title":"Non-small cell lung carcinomas with diffuse coexpression of TTF1 and p40: clinicopathological and genomic features of 14 rare biphenotypic tumours.","date":"2022","source":"Histopathology","url":"https://pubmed.ncbi.nlm.nih.gov/36130728","citation_count":19,"is_preprint":false},{"pmid":"22582081","id":"PMC_22582081","title":"Dual color multiplex TTF-1 + Napsin A and p63 + CK5 immunostaining for subcategorizing of poorly differentiated pulmonary non-small carcinomas into adenocarcinoma and squamous cell carcinoma in fine needle aspiration specimens.","date":"2012","source":"CytoJournal","url":"https://pubmed.ncbi.nlm.nih.gov/22582081","citation_count":19,"is_preprint":false},{"pmid":"30236546","id":"PMC_30236546","title":"The expression of TTF1, CDX2 and ISL1 in 74 poorly differentiated neuroendocrine carcinomas.","date":"2018","source":"Annals of diagnostic pathology","url":"https://pubmed.ncbi.nlm.nih.gov/30236546","citation_count":18,"is_preprint":false},{"pmid":"36519019","id":"PMC_36519019","title":"Association of thyroid transcription factor-1 (TTF-1) expression with efficacy of PD-1/PD-L1 inhibitors plus pemetrexed and platinum chemotherapy in advanced non-squamous non-small cell lung cancer.","date":"2022","source":"Translational lung cancer research","url":"https://pubmed.ncbi.nlm.nih.gov/36519019","citation_count":18,"is_preprint":false},{"pmid":"18355939","id":"PMC_18355939","title":"EGFR, TTF-1 and Mdm2 expression in stage III non-small cell lung cancer: a positive association.","date":"2008","source":"Lung cancer (Amsterdam, Netherlands)","url":"https://pubmed.ncbi.nlm.nih.gov/18355939","citation_count":17,"is_preprint":false},{"pmid":"27322785","id":"PMC_27322785","title":"TTF-1 and PAX5 Are Frequently Expressed in Combined Merkel Cell Carcinoma.","date":"2016","source":"The American Journal of dermatopathology","url":"https://pubmed.ncbi.nlm.nih.gov/27322785","citation_count":17,"is_preprint":false},{"pmid":"32411090","id":"PMC_32411090","title":"TTF-1 Positive Primary Small Cell Carcinoma of the Breast: A Case Report and Review of the Literature.","date":"2020","source":"Frontiers in endocrinology","url":"https://pubmed.ncbi.nlm.nih.gov/32411090","citation_count":16,"is_preprint":false},{"pmid":"34746884","id":"PMC_34746884","title":"Coexpression of ΔNp63/p40 and TTF1 Within Most of the Same Individual Cells Identifies Life-Threatening NSCLC Featuring Squamous and Glandular Biphenotypic Differentiation: Clinicopathologic Correlations.","date":"2021","source":"JTO clinical and research reports","url":"https://pubmed.ncbi.nlm.nih.gov/34746884","citation_count":16,"is_preprint":false},{"pmid":"18487360","id":"PMC_18487360","title":"TTF-1 response element is critical for temporal and spatial regulation and necessary for hormonal regulation of human surfactant protein-A2 promoter activity.","date":"2008","source":"American journal of physiology. Lung cellular and molecular physiology","url":"https://pubmed.ncbi.nlm.nih.gov/18487360","citation_count":16,"is_preprint":false},{"pmid":"37020925","id":"PMC_37020925","title":"TTF-1 Expression and Clinical Outcomes of Combined Chemoimmunotherapy in Patients With Advanced Lung Adenocarcinoma: A Prospective Observational Study.","date":"2023","source":"JTO clinical and research reports","url":"https://pubmed.ncbi.nlm.nih.gov/37020925","citation_count":16,"is_preprint":false},{"pmid":"21867529","id":"PMC_21867529","title":"Altered surfactant homeostasis and recurrent respiratory failure secondary to TTF-1 nuclear targeting defect.","date":"2011","source":"Respiratory research","url":"https://pubmed.ncbi.nlm.nih.gov/21867529","citation_count":16,"is_preprint":false},{"pmid":"34760996","id":"PMC_34760996","title":"NKX2.1 (TTF1) germline mutation associated with pulmonary fibrosis and lung cancer.","date":"2021","source":"ERJ open research","url":"https://pubmed.ncbi.nlm.nih.gov/34760996","citation_count":15,"is_preprint":false},{"pmid":"29313264","id":"PMC_29313264","title":"Positivity for GATA3 and TTF-1 (SPT24), and Negativity for Monoclonal PAX8 Expand the Biomarker Profile of the Solid Cell Nests of the Thyroid Gland.","date":"2018","source":"Endocrine pathology","url":"https://pubmed.ncbi.nlm.nih.gov/29313264","citation_count":15,"is_preprint":false},{"pmid":"31388196","id":"PMC_31388196","title":"When tumor doesn't read textbook. Third case of TTF1 and p40 co-expression in the same tumour cells in a non-small cell carcinoma. A potential new entity to consider?","date":"2019","source":"Pathologica","url":"https://pubmed.ncbi.nlm.nih.gov/31388196","citation_count":15,"is_preprint":false},{"pmid":"31713988","id":"PMC_31713988","title":"Application of GATA 3 and TTF-1 in differentiating parathyroid and thyroid nodules on cytology specimens.","date":"2019","source":"Diagnostic cytopathology","url":"https://pubmed.ncbi.nlm.nih.gov/31713988","citation_count":15,"is_preprint":false},{"pmid":"30194207","id":"PMC_30194207","title":"TTF-1 Expression Predicts the Merit of Additional Antiangiogenic Treatment in Non-squamous Non-small Cell Lung Cancer.","date":"2018","source":"Anticancer research","url":"https://pubmed.ncbi.nlm.nih.gov/30194207","citation_count":15,"is_preprint":false},{"pmid":"25722034","id":"PMC_25722034","title":"Co-expression of TTF-1 and neuroendocrine markers in the human fetal lung and pulmonary neuroendocrine tumors.","date":"2015","source":"Acta histochemica","url":"https://pubmed.ncbi.nlm.nih.gov/25722034","citation_count":14,"is_preprint":false},{"pmid":"12684771","id":"PMC_12684771","title":"Pulmonary well-differentiated fetal adenocarcinoma expressing lineage-specific transcription factors (TTF-1 and GATA-6) to respiratory epithelial differentiation: an immunohistochemical and ultrastructural study.","date":"2003","source":"Virchows Archiv : an international journal of pathology","url":"https://pubmed.ncbi.nlm.nih.gov/12684771","citation_count":13,"is_preprint":false},{"pmid":"22495359","id":"PMC_22495359","title":"IMP3, NESP55, TTF-1 and CDX2 serve as an immunohistochemical panel in the distinction among small-cell carcinoma, gastrointestinal carcinoid, and pancreatic endocrine tumor metastasized to the liver.","date":"2012","source":"Applied immunohistochemistry & molecular morphology : AIMM","url":"https://pubmed.ncbi.nlm.nih.gov/22495359","citation_count":13,"is_preprint":false},{"pmid":"15912575","id":"PMC_15912575","title":"Aberrant expression of TTF-1 and forkhead factor HFH-4 in atrophic gastritis and ciliated metaplasia suggests gastric broncho-pulmonary transdetermination.","date":"2005","source":"The Journal of pathology","url":"https://pubmed.ncbi.nlm.nih.gov/15912575","citation_count":13,"is_preprint":false},{"pmid":"25873201","id":"PMC_25873201","title":"TTF-1 and napsin A on cell blocks and supernatants of pleural fluids for labeling malignant effusions.","date":"2015","source":"Respirology (Carlton, Vic.)","url":"https://pubmed.ncbi.nlm.nih.gov/25873201","citation_count":13,"is_preprint":false},{"pmid":"21143907","id":"PMC_21143907","title":"TTF-1 regulates α5 nicotinic acetylcholine receptor (nAChR) subunits in proximal and distal lung epithelium.","date":"2010","source":"Respiratory research","url":"https://pubmed.ncbi.nlm.nih.gov/21143907","citation_count":13,"is_preprint":false},{"pmid":"39377914","id":"PMC_39377914","title":"TTF-1 is a highly sensitive but not fully specific marker for pulmonary and thyroidal cancer: a tissue microarray study evaluating more than 17,000 tumors from 152 different tumor entities.","date":"2024","source":"Virchows Archiv : an international journal of pathology","url":"https://pubmed.ncbi.nlm.nih.gov/39377914","citation_count":12,"is_preprint":false},{"pmid":"28745797","id":"PMC_28745797","title":"Expressions and significances of TTF-1 and PTEN in early endometrial cancer.","date":"2017","source":"European review for medical and pharmacological sciences","url":"https://pubmed.ncbi.nlm.nih.gov/28745797","citation_count":12,"is_preprint":false},{"pmid":"33581550","id":"PMC_33581550","title":"SMARCA4 (BRG1) and SMARCB1 (INI1) expression in TTF-1 negative neuroendocrine carcinomas including merkel cell carcinoma.","date":"2021","source":"Pathology, research and practice","url":"https://pubmed.ncbi.nlm.nih.gov/33581550","citation_count":12,"is_preprint":false},{"pmid":"33733343","id":"PMC_33733343","title":"An algorithmic approach utilizing CK7, TTF1, beta-catenin, CDX2, and SSTR2A can help differentiate between gastrointestinal and pulmonary neuroendocrine carcinomas.","date":"2021","source":"Virchows Archiv : an international journal of pathology","url":"https://pubmed.ncbi.nlm.nih.gov/33733343","citation_count":12,"is_preprint":false},{"pmid":"22171128","id":"PMC_22171128","title":"Inhibition of tumor angiogenesis by TTF1 from extract of herbal medicine.","date":"2011","source":"World journal of gastroenterology","url":"https://pubmed.ncbi.nlm.nih.gov/22171128","citation_count":12,"is_preprint":false},{"pmid":"31135446","id":"PMC_31135446","title":"The Incidence of Labelling of Non-Lung Adenocarcinomas With Antibodies Against TTF-1 and Diagnostic Implications.","date":"2020","source":"Applied immunohistochemistry & molecular morphology : AIMM","url":"https://pubmed.ncbi.nlm.nih.gov/31135446","citation_count":12,"is_preprint":false},{"pmid":"18071837","id":"PMC_18071837","title":"Mutational analysis of thyroid transcription factor-1 gene (TTF-1) in lung carcinomas.","date":"2007","source":"In vitro cellular & developmental biology. Animal","url":"https://pubmed.ncbi.nlm.nih.gov/18071837","citation_count":12,"is_preprint":false},{"pmid":"8267599","id":"PMC_8267599","title":"Effect of salt concentration on TTF-1 HD binding to specific and non-specific DNA sequences.","date":"1993","source":"Biochemical and biophysical research communications","url":"https://pubmed.ncbi.nlm.nih.gov/8267599","citation_count":11,"is_preprint":false},{"pmid":"18626520","id":"PMC_18626520","title":"The value of immunohistochemical expression of TTF-1, CK7 and CK20 in the diagnosis of primary and secondary lung carcinomas.","date":"2008","source":"Saudi medical journal","url":"https://pubmed.ncbi.nlm.nih.gov/18626520","citation_count":11,"is_preprint":false},{"pmid":"34233113","id":"PMC_34233113","title":"Correlation of TTF-1 immunoexpression and EGFR mutation spectrum in non-small cell lung carcinoma.","date":"2021","source":"Journal of pathology and translational medicine","url":"https://pubmed.ncbi.nlm.nih.gov/34233113","citation_count":11,"is_preprint":false},{"pmid":"21637920","id":"PMC_21637920","title":"TTF1-induced apoptosis of HepG-2 cells through a mitochondrial pathway.","date":"2011","source":"Oncology reports","url":"https://pubmed.ncbi.nlm.nih.gov/21637920","citation_count":11,"is_preprint":false},{"pmid":"29373917","id":"PMC_29373917","title":"Immunohistochemical and Biochemical Expression Patterns of TTF-1, RAGE, GLUT-1 and SOX2 in HCV-Associated Hepatocellular Carcinomas.","date":"2018","source":"Asian Pacific journal of cancer prevention : APJCP","url":"https://pubmed.ncbi.nlm.nih.gov/29373917","citation_count":11,"is_preprint":false},{"pmid":"22174936","id":"PMC_22174936","title":"TTF-1 action on the transcriptional regulation of cyclooxygenase-2 gene in the rat brain.","date":"2011","source":"PloS one","url":"https://pubmed.ncbi.nlm.nih.gov/22174936","citation_count":10,"is_preprint":false},{"pmid":"30631609","id":"PMC_30631609","title":"TTF1 Expression in Pulmonary Metastatic Rectal Adenocarcinoma.","date":"2018","source":"Case reports in gastrointestinal medicine","url":"https://pubmed.ncbi.nlm.nih.gov/30631609","citation_count":10,"is_preprint":false},{"pmid":"31428934","id":"PMC_31428934","title":"REG4 is an indicator for KRAS mutant lung adenocarcinoma with TTF-1 low expression.","date":"2019","source":"Journal of cancer research and clinical oncology","url":"https://pubmed.ncbi.nlm.nih.gov/31428934","citation_count":10,"is_preprint":false},{"pmid":"31206846","id":"PMC_31206846","title":"The utility of TTF-1, napsin A, CK5 and p63 staining in the sub-classification of non-small cell carcinoma of the lung.","date":"2019","source":"Cytopathology : official journal of the British Society for Clinical Cytology","url":"https://pubmed.ncbi.nlm.nih.gov/31206846","citation_count":10,"is_preprint":false},{"pmid":"32045390","id":"PMC_32045390","title":"CDX2, SATB2, GATA3, TTF1, and PAX8 Immunohistochemistry in Krukenberg Tumors.","date":"2020","source":"International journal of gynecological pathology : official journal of the International Society of Gynecological Pathologists","url":"https://pubmed.ncbi.nlm.nih.gov/32045390","citation_count":9,"is_preprint":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":55939,"output_tokens":5804,"usd":0.127439},"stage2":{"model":"claude-opus-4-6","input_tokens":9393,"output_tokens":4052,"usd":0.222397},"total_usd":0.349836,"stage1_batch_id":"msgbatch_01RPbVc9PDH9zQmYK5Hs6srm","stage2_batch_id":"msgbatch_01JVbVLzeKN2yVrsGp3zC8aM","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 1991,\n      \"finding\": \"TTF-1 (a homeodomain-containing transcription factor) activates thyroglobulin and thyroperoxidase gene promoters in differentiated thyroid cell lines, and its mRNA/protein show clear nuclear localization in thyroid, lung, and restricted brain regions from the earliest stages of organ differentiation.\",\n      \"method\": \"In situ hybridization, immunohistochemistry, promoter activation assays in thyroid cell lines\",\n      \"journal\": \"Development\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — foundational study with multiple orthogonal methods (ISH, IHC, reporter assays), widely replicated\",\n      \"pmids\": [\"1811929\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2004,\n      \"finding\": \"TAZ (transcriptional co-activator with PDZ-binding motif) directly interacts with the NH2-terminal domain of TTF-1 via its WW domain, and this interaction synergistically activates surfactant protein-C (SP-C) promoter transcription in lung epithelial cells.\",\n      \"method\": \"Mammalian two-hybrid assay, GST pull-down, co-transfection luciferase reporter assay, deletion analysis\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 — reciprocal pull-down plus deletion mapping plus functional reporter assay in same study\",\n      \"pmids\": [\"14970209\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2001,\n      \"finding\": \"CBP/p300 and SRC-1 interact with TTF-1 in vitro and in lung type II cell nuclear extracts; PKA-mediated phosphorylation of TTF-1 facilitates this interaction and leads to TTF-1 hyperacetylation, enhancing its DNA-binding and transcriptional activation of the SP-A promoter.\",\n      \"method\": \"In vitro GST pull-down, SRC-1 immunodepletion from nuclear extracts, transient transfection reporter assay, PKA catalytic subunit overexpression, adenoviral E1A competition, cAMP-induced acetylation assay\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 — multiple orthogonal biochemical methods in one study demonstrating PTM-dependent co-activator recruitment\",\n      \"pmids\": [\"11713256\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2000,\n      \"finding\": \"ERK directly phosphorylates TTF-1 at three serine residues (identified by in vitro kinase assay and alanine mutagenesis), and the Ras/Raf/MEK/ERK pathway represses TTF-1 transcriptional activity; an additional ERK-independent Ras pathway (via V12N38 Ras) cooperates to produce near-complete loss of TTF-1 function.\",\n      \"method\": \"In vitro kinase assay, site-directed mutagenesis (Ser→Ala), MEK inhibitors (U0126/PD98059), transient transfection reporter assay, Ras effector-region mutants\",\n      \"journal\": \"Molecular and cellular biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 — in vitro phosphorylation reconstituted and confirmed by mutagenesis, plus pharmacological epistasis\",\n      \"pmids\": [\"10733581\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2006,\n      \"finding\": \"PARP-2 (and PARP-1/Ku70/Ku80) co-immunoprecipitate with endogenous TTF-1 in lung epithelial cells; the E domain of PARP-2 interacts with the C-terminal domain of TTF-1; PARP-1 and PARP-2 selectively enhance surfactant protein-B (SP-B) promoter activity when co-expressed with TTF-1.\",\n      \"method\": \"Co-immunoprecipitation from MLE15 cell extracts, mass spectrometry identification, GST domain-mapping pull-down, transient transfection reporter assay\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — reciprocal Co-IP with MS identification plus domain mapping and functional reporter\",\n      \"pmids\": [\"16461352\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1998,\n      \"finding\": \"RET/PTC1 oncogene expression leaves TTF-1 protein levels unchanged but renders TTF-1 transcriptionally inactive (assayed on a synthetic TTF-1-target promoter), indicating posttranslational inactivation of TTF-1 function downstream of RET/PTC1 signaling.\",\n      \"method\": \"Transient transfection reporter assay using synthetic TTF-1 target promoter, Western blot, adoptive overexpression\",\n      \"journal\": \"Cell growth & differentiation\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — clean loss-of-function/gain-of-function with reporter, single lab\",\n      \"pmids\": [\"9438393\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2004,\n      \"finding\": \"TTF-1 binds to a specific site in the RET promoter; HSCR-associated RET promoter SNPs that overlap the TTF-1 binding site decrease TTF-1-activated RET transcription; a patient-derived TTF-1 missense mutation (Gly322Ser) compromises transactivation of HSCR-associated RET promoter haplotypes.\",\n      \"method\": \"Luciferase reporter assay, electrophoretic mobility shift assay (EMSA), weighted logistic regression on SNP data, functional mutation analysis\",\n      \"journal\": \"Human molecular genetics\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 — EMSA demonstrating direct binding plus functional reporter assay plus patient mutation, multiple methods\",\n      \"pmids\": [\"15548547\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2001,\n      \"finding\": \"TTF-1 binds to and transactivates the erbB-2 and LHRH gene promoters in hypothalamic neurons, while repressing transcription of the preproenkephalin gene; hypothalamic TTF-1 expression increases transiently prior to puberty onset, suggesting a role in the transcriptional control of female sexual development.\",\n      \"method\": \"Electrophoretic mobility shift assay (DNA binding), promoter-reporter transactivation assay, intracerebroventricular antisense oligonucleotide knockdown, in situ hybridization, immunohistochemistry\",\n      \"journal\": \"Molecular and cellular neurosciences\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 — EMSA plus reporter plus in vivo antisense KD with phenotypic readout, multiple orthogonal methods\",\n      \"pmids\": [\"11161473\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2006,\n      \"finding\": \"Neuron-specific deletion of Ttf1 in mice causes delayed puberty, reduced reproductive capacity, and a short reproductive span without basal ganglia/hypothalamic morphological defects, demonstrating a post-morphogenic role of TTF-1 in hypothalamic neuroendocrine control of female reproduction.\",\n      \"method\": \"Conditional neuron-specific Ttf1 knockout mice, gene expression profiling, behavioral/reproductive phenotyping\",\n      \"journal\": \"The Journal of neuroscience\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — clean conditional KO with defined reproductive phenotype and gene-expression mechanistic follow-up\",\n      \"pmids\": [\"17182767\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2002,\n      \"finding\": \"TTF-1 activates PACAP gene transcription by binding to six of seven conserved TTF-1-binding motifs in the PACAP 5'-flanking region; deletion of the core motif at -369 abolishes transactivation; intracerebroventricular antisense TTF-1 oligonucleotide knockdown significantly decreases hypothalamic PACAP mRNA.\",\n      \"method\": \"EMSA (TTF-1 homeodomain binding to PACAP promoter sites), promoter-reporter deletion/mutational analysis, intracerebroventricular antisense KD with RNase protection assay\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 — EMSA plus deletion reporter plus in vivo antisense KD, multiple orthogonal methods\",\n      \"pmids\": [\"12122016\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2011,\n      \"finding\": \"MYBPH is a transcriptional target of TTF-1; TTF-1 drives MYBPH expression and MYBPH inhibits ROCK1 through direct physical interaction, thereby suppressing myosin regulatory light chain phosphorylation and LIMK activation, reducing actomyosin-driven single-cell motility and cancer metastasis.\",\n      \"method\": \"Chromatin immunoprecipitation (TTF-1 on MYBPH promoter), co-immunoprecipitation (MYBPH–ROCK1), in vitro kinase assays, shRNA knockdown, cell motility assays, mouse metastasis models\",\n      \"journal\": \"The EMBO journal\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 — ChIP plus reciprocal Co-IP plus kinase assay plus in vivo model, multiple orthogonal methods\",\n      \"pmids\": [\"22085929\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1994,\n      \"finding\": \"The isolated TTF-1 homeodomain (TTF-1HD) binds DNA as a monomer; its conformational stability is low (Tm 42°C, ΔG ~1.4 kcal/mol) and helical flexibility is important for DNA-binding activity, as small reductions in α-helical content significantly diminish DNA binding.\",\n      \"method\": \"Circular dichroism thermal denaturation, isothermal urea unfolding, DNA-binding assays\",\n      \"journal\": \"FEBS letters\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 — biophysical structural characterization with direct correlation to DNA-binding function\",\n      \"pmids\": [\"7957942\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1993,\n      \"finding\": \"The TTF-1 homeodomain (TTF-1HD) exists as a monomer in solution and binds DNA as a monomer; at physiological salt conditions, its affinity for specific DNA sequences is at least 1000-fold higher than for non-specific sequences.\",\n      \"method\": \"Biochemical DNA-binding assays with titration of KCl concentration, gel-shift (EMSA)\",\n      \"journal\": \"Biochemical and biophysical research communications\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 — in vitro reconstitution of specific vs. non-specific DNA binding, quantitative affinity measurements\",\n      \"pmids\": [\"8267599\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1998,\n      \"finding\": \"The TTF-1/T/EBP gene is autoregulated: the TTF-1 promoter contains ~24 putative TTF-1 binding sites, and co-transfection of a TTF-1 expression vector activates its own promoter reporter in HepG2 cells that lack endogenous TTF-1; multiple promoters and alternative splicing generate a family of TTF-1 mRNAs.\",\n      \"method\": \"Cotransfection reporter assay, RNase protection assay, Northern blot, cDNA cloning/sequencing\",\n      \"journal\": \"Endocrinology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — reporter assay plus molecular characterization, single lab\",\n      \"pmids\": [\"9528987\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2009,\n      \"finding\": \"Three TTF-1/NKX2-1 missense mutations (L176V, P202L, Q210P) cause loss of transactivation capacity on the human thyroglobulin enhancer/promoter; deficient activity of P202L is completely rescued by cotransfected wild-type PAX8, whereas L176V and Q210P abolish the PAX8 synergism.\",\n      \"method\": \"Transient transfection transactivation assay on thyroglobulin enhancer/promoter reporter, cotransfection with PAX8\",\n      \"journal\": \"Human molecular genetics\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — functional mutagenesis with epistatic PAX8 rescue, multiple patient mutations tested\",\n      \"pmids\": [\"19336474\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1995,\n      \"finding\": \"Antisense oligonucleotide-mediated blockade of TTF-1 in FRTL-5 thyroid cells reduces TSH- and IGF-I-stimulated cell proliferation (DNA synthesis and cell counting) by ~65%, demonstrating that TTF-1 expression is required for thyroid cell proliferation via the cAMP pathway.\",\n      \"method\": \"Antisense oligonucleotide treatment, DNA synthesis assay, cell counting\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — loss-of-function with defined cellular phenotype, single lab\",\n      \"pmids\": [\"7559458\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2011,\n      \"finding\": \"TTF-1 transactivates the α5 nicotinic acetylcholine receptor (nAChR) subunit promoter by binding specific TTF-1 response elements; site-directed mutagenesis of these elements abolishes TTF-1-driven α5 transcription in proximal and distal lung epithelial cell lines.\",\n      \"method\": \"Promoter-reporter assay, site-directed mutagenesis of TTF-1 response elements, exogenous TTF-1 overexpression\",\n      \"journal\": \"Respiratory research\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — mutagenesis of binding sites plus gain-of-function, single lab\",\n      \"pmids\": [\"21143907\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2008,\n      \"finding\": \"In the TTF-1 proximal promoter, ZBP-89, Sp1/Sp3, and TTF-1 itself bind functional sites identified by EMSA and ChIP; TNF-α inhibits TTF-1 gene transcription and promoter activity, suppressing TTF-1 binding to its own promoter while increasing threonine phosphorylation of Sp1, without altering Sp1 or HNF-3 protein levels.\",\n      \"method\": \"Promoter deletion analysis, EMSA, chromatin immunoprecipitation (ChIP), mutational analysis, TNF-α treatment of H441 and primary alveolar type II cells\",\n      \"journal\": \"American journal of physiology. Lung cellular and molecular physiology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 — ChIP plus EMSA plus mutagenesis plus cytokine perturbation, multiple orthogonal methods\",\n      \"pmids\": [\"21784970\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2011,\n      \"finding\": \"TTF-1 inhibits COX-2 gene transcription in hypothalamic astrocytes and endothelial cells by binding to specific sites in the COX-2 promoter; intracerebroventricular antisense TTF-1 knockdown increases COX-2 synthesis in non-neuronal hypothalamic cells and causes hyperthermia.\",\n      \"method\": \"EMSA (TTF-1 binding to COX-2 promoter sites), promoter-reporter assay, intracerebroventricular antisense oligonucleotide knockdown, double immunohistochemistry, body temperature measurement\",\n      \"journal\": \"PloS one\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 — EMSA plus reporter plus in vivo antisense KD with thermoregulatory phenotype\",\n      \"pmids\": [\"22174936\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"TTF-1 and its co-regulators FoxA2 and Gata-6 transcriptionally activate the Claudin-6 (Cldn6) promoter in both proximal airway (Beas2B) and distal alveolar (A-549) epithelial cell lines, demonstrating that Cldn6 is a direct transcriptional target of TTF-1 during lung organogenesis.\",\n      \"method\": \"Promoter-reporter assay (0.5, 1.0, 2.0-kb Cldn6 promoter fragments co-transfected with TTF-1 expression vectors), immunofluorescence co-localization\",\n      \"journal\": \"Respiratory research\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — reporter assay with multiple promoter lengths, single lab\",\n      \"pmids\": [\"24970044\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2008,\n      \"finding\": \"The TTF-1 response element (TBE at -171 bp) in the hSP-A2 promoter is essential for lung cell-specific, developmental, and hormonal (cAMP/IL-1/dexamethasone) regulation of SP-A2 expression in vivo, demonstrated in transgenic mice where TBE mutation abolishes detectable transgene expression and hormonal responsiveness in fetal lung.\",\n      \"method\": \"Transgenic mouse reporter assay (hSP-A2-hGH reporter with wild-type or TBE-mutant promoters), cultured fetal lung explant hormone treatment\",\n      \"journal\": \"American journal of physiology. Lung cellular and molecular physiology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 — in vivo transgenic promoter mutagenesis with multiple hormonal readouts\",\n      \"pmids\": [\"18487360\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"BRN2, a neural lineage-specific homeoprotein, directly binds the TTF-1 isoform 2 promoter (confirmed by ChIP) and substantially upregulates TTF-1 expression in small-cell lung cancer (SCLC) cells; BRN2 knockdown considerably downregulates TTF-1 in SCLC, whereas FOXA1/2 weakly activate the TTF-1 promoter.\",\n      \"method\": \"TTF-1 promoter reporter assay, chromatin immunoprecipitation (ChIP), siRNA knockdown of BRN2, transfection of expression vectors (BRN2, FOXA1/2, LHX2/6)\",\n      \"journal\": \"Laboratory investigation\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 — ChIP confirming direct binding plus functional reporter plus loss-of-function KD\",\n      \"pmids\": [\"23358112\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"mTOR inhibition promotes TTF-1-dependent redifferentiation of thyroid carcinoma cells: siRNA knockdown of TTF-1 completely abrogates mTOR inhibitor-induced sodium-iodide symporter (NIS) expression and increased iodine uptake, placing TTF-1 as a required transcriptional mediator of mTOR-controlled thyroid redifferentiation.\",\n      \"method\": \"mTOR inhibitor treatment of thyroid carcinoma cell lines (BC-PAP, FTC133, TPC1), siRNA knockdown of TTF-1, NIS mRNA/protein assay, iodine uptake assay\",\n      \"journal\": \"The Journal of clinical endocrinology and metabolism\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — siRNA epistasis (TTF-1 KD abrogates NIS induction) with functional iodine uptake readout\",\n      \"pmids\": [\"24712572\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2011,\n      \"finding\": \"Defective nuclear targeting of TTF-1 protein (TTF-1 retained in cytoplasm of type II cells rather than nucleus) is associated with markedly reduced surfactant protein-B synthesis and disrupted surfactant homeostasis in an infant with recurrent respiratory failure, functionally linking TTF-1 nuclear localization to SP-B transcription.\",\n      \"method\": \"Confocal immunofluorescence microscopy of lung biopsy, SP-B kinetic stable-isotope synthesis assay, ABCA3/SFTPB/NKX2.1 gene sequencing\",\n      \"journal\": \"Respiratory research\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — direct localization experiment tied to functional surfactant phenotype, single clinical case with mechanistic follow-up\",\n      \"pmids\": [\"21867529\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"TTF-1 (NKX2-1) is a homeodomain transcription factor that binds specific DNA motifs as a monomer to directly activate lung surfactant protein genes (SP-A, SP-B, SP-C) and thyroid-specific genes (thyroglobulin, thyroperoxidase, NIS), with its transcriptional activity modulated by PKA phosphorylation, acetylation by CBP/p300, recruitment of co-activators SRC-1, TAZ, and PARP-2, and repression by ERK-mediated phosphorylation downstream of Ras/Raf signaling; nuclear localization of TTF-1 is required for surfactant homeostasis, and in the hypothalamus TTF-1 activates LHRH, erbB-2, and PACAP promoters while repressing preproenkephalin and COX-2, thereby controlling female sexual development and neuroendocrine function.\"\n}\n```","stage2_raw":"```json\n{\n  \"mechanistic_narrative\": \"TTF-1 (NKX2-1) is a homeodomain transcription factor that serves as a master regulator of tissue-specific gene expression in the thyroid, lung, and hypothalamus, coordinating differentiation, surfactant homeostasis, neuroendocrine function, and cell proliferation. It binds DNA as a monomer with high sequence specificity and activates thyroglobulin, thyroperoxidase, surfactant protein (SP-A, SP-B, SP-C), RET, PACAP, LHRH, erbB-2, Claudin-6, MYBPH, and α5 nAChR promoters while repressing preproenkephalin and COX-2 transcription [PMID:1811929, PMID:12122016, PMID:11161473, PMID:22174936, PMID:22085929, PMID:15548547]. Its transcriptional output is positively regulated by PKA-dependent phosphorylation and acetylation via CBP/p300 and SRC-1, and by co-activators TAZ and PARP-1/PARP-2, whereas ERK-mediated phosphorylation downstream of Ras/Raf signaling and RET/PTC1 oncogene activity repress TTF-1 function post-translationally [PMID:11713256, PMID:14970209, PMID:16461352, PMID:10733581, PMID:9438393]. Neuron-specific deletion in mice causes delayed puberty and reduced reproductive capacity without gross morphological defects, establishing a post-morphogenic role in hypothalamic control of female reproduction [PMID:17182767].\",\n  \"teleology\": [\n    {\n      \"year\": 1991,\n      \"claim\": \"Establishing TTF-1 as a tissue-restricted transcription factor: prior to this work, the gene targets and expression domains of TTF-1 were unknown; this study showed it activates thyroglobulin and thyroperoxidase promoters and is expressed in thyroid, lung, and select brain regions from the earliest stages of organogenesis.\",\n      \"evidence\": \"In situ hybridization, immunohistochemistry, and promoter-reporter assays in thyroid cell lines\",\n      \"pmids\": [\"1811929\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Lung and brain target genes not yet identified\", \"No loss-of-function evidence for developmental necessity\"]\n    },\n    {\n      \"year\": 1993,\n      \"claim\": \"Resolving TTF-1's DNA-binding mode: it was unclear whether TTF-1 bound DNA as a dimer like many homeodomain proteins; biophysical analysis demonstrated monomeric binding with ≥1000-fold specificity over non-specific DNA, and later work showed the homeodomain's low conformational stability is critical for binding activity.\",\n      \"evidence\": \"Quantitative EMSA with salt titration (1993); circular dichroism thermal denaturation and urea unfolding coupled to DNA-binding assays (1994)\",\n      \"pmids\": [\"8267599\", \"7957942\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"No high-resolution structure of full-length TTF-1 on DNA\", \"Contribution of flanking domains to specificity unexplored\"]\n    },\n    {\n      \"year\": 1995,\n      \"claim\": \"Demonstrating a proliferative requirement: TTF-1 had been characterized only as a differentiation factor; antisense knockdown revealed it is also required for TSH- and IGF-I-stimulated thyroid cell proliferation, broadening its role beyond terminal differentiation.\",\n      \"evidence\": \"Antisense oligonucleotide treatment of FRTL-5 thyroid cells with DNA synthesis and cell counting assays\",\n      \"pmids\": [\"7559458\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Antisense approach lacks specificity controls of modern RNAi/knockout\", \"Downstream proliferative targets not identified\"]\n    },\n    {\n      \"year\": 1998,\n      \"claim\": \"Identifying oncogene-mediated post-translational repression and autoregulation: it was unknown how oncogenic signaling affects TTF-1; RET/PTC1 was shown to inactivate TTF-1 without reducing its protein level, and separately, TTF-1 was found to positively autoregulate its own promoter.\",\n      \"evidence\": \"Reporter assays with RET/PTC1 overexpression (1998); TTF-1 co-transfection activating its own promoter in HepG2 cells (1998)\",\n      \"pmids\": [\"9438393\", \"9528987\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Mechanism of RET/PTC1-mediated inactivation not resolved at phosphorylation/PTM level\", \"Autoregulation not confirmed by ChIP in endogenous context\"]\n    },\n    {\n      \"year\": 2000,\n      \"claim\": \"Mapping the ERK phosphorylation sites that repress TTF-1: the post-translational mechanism by which Ras signaling inhibits TTF-1 was unknown; ERK was shown to directly phosphorylate three serines on TTF-1, with an additional ERK-independent Ras pathway cooperating for near-complete inactivation.\",\n      \"evidence\": \"In vitro kinase assay, Ser→Ala mutagenesis, MEK inhibitors, and Ras effector-domain mutants in reporter assays\",\n      \"pmids\": [\"10733581\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Identity of the ERK-independent Ras effector pathway not resolved\", \"In vivo phosphorylation stoichiometry unknown\"]\n    },\n    {\n      \"year\": 2001,\n      \"claim\": \"Defining the co-activator complex and PKA-dependent acetylation switch: it was unclear how cAMP/PKA signaling enhances TTF-1 activity; CBP/p300 and SRC-1 were shown to interact with TTF-1 in lung type II cells, with PKA phosphorylation promoting this interaction and TTF-1 hyperacetylation, thereby boosting SP-A transactivation.\",\n      \"evidence\": \"GST pull-down, immunodepletion, PKA overexpression, adenoviral E1A competition, and cAMP-induced acetylation assays\",\n      \"pmids\": [\"11713256\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Specific acetylation sites on TTF-1 not mapped\", \"Relative contributions of SRC-1 vs. CBP/p300 not dissected in vivo\"]\n    },\n    {\n      \"year\": 2001,\n      \"claim\": \"Extending TTF-1 into neuroendocrine gene regulation: it was unknown whether TTF-1 controlled hypothalamic genes; TTF-1 was shown to activate LHRH and erbB-2 promoters and repress preproenkephalin in hypothalamic neurons, with expression peaking before puberty.\",\n      \"evidence\": \"EMSA, promoter-reporter assays, intracerebroventricular antisense knockdown, ISH, and IHC in rat hypothalamus\",\n      \"pmids\": [\"11161473\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Direct chromatin occupancy at hypothalamic targets not shown (no ChIP)\", \"Mechanism of transcriptional repression not characterized\"]\n    },\n    {\n      \"year\": 2002,\n      \"claim\": \"Identifying PACAP as a direct TTF-1 target in the hypothalamus: this connected TTF-1 to neuropeptide circuits beyond LHRH, showing binding to six motifs in the PACAP promoter and demonstrating in vivo dependence of PACAP mRNA on TTF-1.\",\n      \"evidence\": \"EMSA, promoter deletion/mutation reporter analysis, intracerebroventricular antisense knockdown with RNase protection assay\",\n      \"pmids\": [\"12122016\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"No ChIP confirmation of occupancy in vivo\", \"Functional consequence of PACAP reduction on puberty not tested\"]\n    },\n    {\n      \"year\": 2004,\n      \"claim\": \"Recruiting TAZ as a co-activator for lung surfactant gene activation and linking TTF-1 to RET in Hirschsprung disease: TAZ was shown to synergize with TTF-1 on the SP-C promoter via WW domain–N-terminal interaction; separately, TTF-1 was found to directly bind the RET promoter, with HSCR-associated SNPs and a patient TTF-1 mutation compromising this activation.\",\n      \"evidence\": \"Mammalian two-hybrid, GST pull-down, deletion mapping, reporter assays (TAZ study); EMSA, reporter assay, logistic regression on HSCR SNPs (RET study)\",\n      \"pmids\": [\"14970209\", \"15548547\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"TAZ interaction not validated by endogenous Co-IP\", \"Functional impact of RET promoter regulation on enteric nervous system development not shown in animal model\"]\n    },\n    {\n      \"year\": 2006,\n      \"claim\": \"Identifying PARP-1/PARP-2 as endogenous TTF-1 partners that selectively enhance SP-B: the co-activator landscape for SP-B was undefined; PARP-2 was found to interact with TTF-1's C-terminal domain and specifically boost SP-B promoter activity, together with PARP-1 and Ku70/Ku80 identified by mass spectrometry.\",\n      \"evidence\": \"Co-immunoprecipitation from MLE15 cells, mass spectrometry, GST domain mapping, reporter assay\",\n      \"pmids\": [\"16461352\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Whether PARP enzymatic activity (PARylation) is required for co-activation not tested\", \"In vivo relevance in PARP-2 knockout lungs not assessed\"]\n    },\n    {\n      \"year\": 2006,\n      \"claim\": \"Establishing an in vivo post-morphogenic role of TTF-1 in female reproduction: conditional neuron-specific Ttf1 knockout mice showed delayed puberty and shortened reproductive lifespan without hypothalamic structural defects, proving TTF-1 acts beyond early brain patterning.\",\n      \"evidence\": \"Conditional neuron-specific Ttf1 knockout mice with reproductive phenotyping and gene expression profiling\",\n      \"pmids\": [\"17182767\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Specific neuronal subtypes requiring TTF-1 not resolved\", \"Direct targets mediating the reproductive phenotype not fully identified\"]\n    },\n    {\n      \"year\": 2008,\n      \"claim\": \"Demonstrating that the TTF-1 binding element is essential for in vivo lung-specific and hormonally regulated SP-A2 expression: transgenic mice with a mutated TBE showed complete loss of SP-A2 transgene expression and hormonal responsiveness, confirming TTF-1 as a non-redundant in vivo driver of surfactant gene regulation.\",\n      \"evidence\": \"Transgenic mouse reporter with wild-type vs. TBE-mutant hSP-A2 promoters, fetal lung explant hormone treatment\",\n      \"pmids\": [\"18487360\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Whether other TTF-1 sites compensate for TBE loss at endogenous locus not tested\", \"Chromatin accessibility changes at mutant TBE not examined\"]\n    },\n    {\n      \"year\": 2011,\n      \"claim\": \"Expanding TTF-1's role to anti-metastatic transcriptional programs and hypothalamic thermoregulation: TTF-1 was shown to directly activate MYBPH transcription (suppressing ROCK1-driven cell motility and metastasis) and to repress COX-2 in hypothalamic non-neuronal cells (controlling body temperature).\",\n      \"evidence\": \"ChIP on MYBPH promoter, MYBPH–ROCK1 Co-IP, kinase assays, mouse metastasis model (MYBPH study); EMSA, reporter, in vivo antisense KD with temperature measurement (COX-2 study)\",\n      \"pmids\": [\"22085929\", \"22174936\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"MYBPH-independent anti-metastatic targets of TTF-1 not delineated\", \"Molecular mechanism of COX-2 repression (co-repressor identity) not defined\"]\n    },\n    {\n      \"year\": 2011,\n      \"claim\": \"Linking TTF-1 nuclear localization directly to surfactant homeostasis in human disease: cytoplasmic retention of TTF-1 protein in type II pneumocytes was associated with markedly reduced SP-B synthesis and respiratory failure in an infant, functionally connecting nuclear import to transcriptional output.\",\n      \"evidence\": \"Confocal immunofluorescence of lung biopsy, stable-isotope SP-B kinetic assay, gene sequencing\",\n      \"pmids\": [\"21867529\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Mechanism causing cytoplasmic retention not identified\", \"Single clinical case without genetic rescue or cell-based validation\", \"Causative mutation or transport defect not established\"]\n    },\n    {\n      \"year\": 2014,\n      \"claim\": \"Positioning TTF-1 as the required mediator of mTOR inhibitor-induced thyroid redifferentiation: siRNA knockdown of TTF-1 completely abolished NIS re-expression and iodine uptake induced by mTOR inhibition, establishing TTF-1 downstream of mTOR signaling in thyroid cancer cells.\",\n      \"evidence\": \"mTOR inhibitor treatment of thyroid carcinoma lines, TTF-1 siRNA epistasis, NIS mRNA/protein and iodine uptake assays\",\n      \"pmids\": [\"24712572\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Whether mTOR controls TTF-1 protein stability, phosphorylation, or transcription not resolved\", \"In vivo relevance for radioiodine therapy not demonstrated\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"Unresolved: the full genome-wide target repertoire of TTF-1 across its three expression domains (thyroid, lung, brain) has not been systematically defined by ChIP-seq; the structural basis for how post-translational modifications alter TTF-1 conformation and co-activator selectivity remains unknown; and the nuclear import mechanism whose failure causes surfactant disease has not been identified.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"No genome-wide ChIP-seq across tissue types\", \"No full-length TTF-1 crystal or cryo-EM structure\", \"Nuclear import pathway and transport signals not characterized\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0003677\", \"supporting_discovery_ids\": [0, 6, 7, 9, 10, 11, 12, 17, 18, 20]},\n      {\"term_id\": \"GO:0140110\", \"supporting_discovery_ids\": [0, 1, 2, 6, 7, 9, 10, 14, 16, 18, 19, 20, 22]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005634\", \"supporting_discovery_ids\": [0, 23]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-74160\", \"supporting_discovery_ids\": [0, 1, 2, 6, 7, 9, 10, 14, 16, 18, 19, 20, 22]},\n      {\"term_id\": \"R-HSA-162582\", \"supporting_discovery_ids\": [3, 5, 22]},\n      {\"term_id\": \"R-HSA-1266738\", \"supporting_discovery_ids\": [0, 8, 19]}\n    ],\n    \"complexes\": [],\n    \"partners\": [\"CBP\", \"SRC1\", \"TAZ\", \"PARP1\", \"PARP2\", \"PAX8\", \"BRN2\", \"FOXA2\"],\n    \"other_free_text\": []\n  }\n}\n```"}