{"gene":"LTBR","run_date":"2026-04-28T18:30:27","timeline":{"discoveries":[{"year":1994,"finding":"Identification of LTBR (lymphotoxin-beta receptor) as a receptor specific for the LT-alpha/LT-beta heteromeric complex on the cell surface, distinct from the p60 and p80 TNF receptors that bind secreted LT-alpha homotrimers.","method":"Receptor binding assay / protein biochemistry","journal":"Science","confidence":"High","confidence_rationale":"Tier 1-2 — original identification paper, foundational discovery replicated across the field","pmids":["8171323"],"is_preprint":false},{"year":1995,"finding":"TRAF2 (LAP1) and TRAF1 (EBI6) associate with the cytoplasmic domain of LTBR; EBV LMP1 co-immunoprecipitates with these TRAF proteins and causes them to localize to LMP1 clusters in the plasma membrane, linking LMP1 transformation to TNFR-family signaling including LTBR.","method":"Co-immunoprecipitation, immunofluorescence localization","journal":"Cell","confidence":"High","confidence_rationale":"Tier 2 — reciprocal co-IP with functional localization, highly cited foundational paper","pmids":["7859281"],"is_preprint":false},{"year":1996,"finding":"TRAF5 binds specifically to the cytoplasmic region of LTBR (but not CD40, TNFR1, TNFR2, Fas, or NGFR) in vitro and co-immunoprecipitates with LTBR when overexpressed in COS7 cells; TRAF5 overexpression activates NF-κB and a dominant-negative truncated TRAF5 partially inhibits LTbetaR-induced NF-κB activation.","method":"In vitro translation binding assay, co-immunoprecipitation in COS7 cells, NF-κB reporter assay","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 2 — multiple orthogonal methods (pull-down, co-IP, functional reporter), highly cited","pmids":["8663299"],"is_preprint":false},{"year":1997,"finding":"TRAF3 is rapidly recruited to the LTBR cytoplasmic domain upon LT-alpha1/beta2 or agonistic anti-LTBR antibody treatment; dominant-negative TRAF3 (lacking RING and zinc finger domains) specifically inhibits LTBR-mediated cell death but not NF-κB activation, establishing TRAF3 as a critical component of the LTBR death-signaling complex and demonstrating two independent signaling pathways downstream of LTBR.","method":"Co-immunoprecipitation, stable overexpression of dominant-negative mutant, cell death assay","journal":"Proceedings of the National Academy of Sciences of the United States of America","confidence":"High","confidence_rationale":"Tier 2 — reciprocal co-IP plus dominant-negative epistasis with specific phenotypic readout","pmids":["9122217"],"is_preprint":false},{"year":1997,"finding":"HCV core protein directly binds the cytoplasmic tail of LTBR; the binding site on LTBR was mapped to a 58-amino-acid region of its cytoplasmic tail and the HCV core binding site was localized to residues 36–91 (hydrophilic region); association was confirmed in mammalian cells by co-immunoprecipitation.","method":"Yeast two-hybrid screen, GST pull-down assay, protein-protein blotting, mammalian co-immunoprecipitation","journal":"Journal of virology","confidence":"High","confidence_rationale":"Tier 1-2 — multiple orthogonal methods including in vitro reconstitution and mammalian co-IP, domain mapping","pmids":["8995654"],"is_preprint":false},{"year":1998,"finding":"LIGHT (TNFSF14), a new TNF superfamily member produced by activated T cells, binds both HVEM and LTBR (the LT-alpha/beta heterotrimer receptor); LIGHT does not form complexes with LT-alpha or LT-beta and HSV gD inhibits HVEM-LIGHT interaction, establishing LIGHT as a dual-receptor ligand in the lymphotoxin system.","method":"Receptor-ligand binding assays, transfection, functional blocking studies","journal":"Immunity","confidence":"High","confidence_rationale":"Tier 2 — multiple binding and functional assays; highly cited foundational paper","pmids":["9462508"],"is_preprint":false},{"year":1999,"finding":"Decoy receptor 3 (TR6/DcR3) specifically binds LIGHT and FasL; TR6 inhibits LIGHT-induced cytotoxicity by blocking LIGHT interactions with both LTBR and HVEM, suppressing LIGHT-mediated apoptosis in HT29 cells that express both receptors.","method":"Immunoprecipitation of recombinant proteins, flow cytometry, cytotoxicity assay","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 2 — multiple assays demonstrating receptor competition and functional consequence","pmids":["10318773"],"is_preprint":false},{"year":2000,"finding":"LTBR (not HVEM) is necessary and sufficient for LIGHT-mediated apoptosis and ICAM-1 induction; LIGHT mutants with selective HveA binding cannot trigger cell death; LTBR (not HveA) recruits TRAF3, and dominant-negative TRAF3 blocks LIGHT-induced death, establishing TRAF3 recruitment as the mechanism propagating LTBR death signals.","method":"Point mutagenesis of LIGHT, receptor-specific antibody blocking, dominant-negative TRAF3 overexpression, cell death assay","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 1-2 — mutagenesis of ligand, receptor-specific blocking antibodies, epistasis via dominant-negative, multiple orthogonal methods","pmids":["10799510"],"is_preprint":false},{"year":2002,"finding":"LTBR ligation activates two distinct NF-κB pathways: (1) canonical IKKβ/NEMO-dependent NF-κB driving proinflammatory genes (VCAM-1, MIP-1β, MIP-2) and expression of p100; (2) non-canonical NIK/IKKα-dependent processing of NF-κB2/p100 to p52 (independent of NEMO/IKKγ), driving lymphoid organogenesis chemokines (SLC, BLC, ELC, SDF1, BAFF).","method":"Genetic epistasis using IKK-deficient cells, dominant-negative kinase mutants, NF-κB reporter assays, chemokine/cytokine expression analysis","journal":"Immunity","confidence":"High","confidence_rationale":"Tier 1-2 — multiple genetic loss-of-function models with specific gene expression readouts; highly cited definitive pathway paper","pmids":["12387745"],"is_preprint":false},{"year":2002,"finding":"NIK and IKKα mediate LTBR-induced NF-κB activation through phosphorylation of the p65 subunit at serine 536 in its transactivation domain 1 (TA1); this phosphorylation is required for transcriptional activation without altering IκB phosphorylation levels or p65 nuclear localization, revealing a distinct mechanism for LTBR-driven NF-κB activity.","method":"Dominant-negative kinase mutants (NIK, IKKα), Gal4-fusion transactivation reporter assay, site-directed mutagenesis of p65-Ser536, phosphorylation detection following LTbetaR stimulation","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 1-2 — mutagenesis, phosphorylation detection, and heterologous reporter assay demonstrating mechanism","pmids":["12419817"],"is_preprint":false},{"year":2006,"finding":"LTBR signaling controls the development and maintenance of tertiary lymphoid organs (TLO) in the pancreas; blockade of TNFSF14 (LIGHT) signaling reduces LTBR-controlled migration factor expression and disrupts TLO organization, preventing diabetes in NOD mice; transgenic TNFSF14 expression in islets rapidly promotes TLO formation even without draining lymph nodes.","method":"In vivo blockade of TNFSF14, transgenic mouse model, gene expression analysis, histology","journal":"Immunity","confidence":"High","confidence_rationale":"Tier 2 — genetic gain- and loss-of-function in vivo with defined cellular and molecular phenotypes","pmids":["16934497"],"is_preprint":false},{"year":2009,"finding":"Hepatic LT-alpha/LT-beta overexpression drives liver inflammation and HCC in mice; HCC development depends on lymphocytes and hepatocyte IKKβ but not TNFR1; in vivo LTbetaR stimulation implicates hepatocytes as the major LT-responsive liver cells; LTbetaR inhibition suppresses HCC formation in LT-transgenic mice with hepatitis.","method":"Liver-specific LTalphabeta transgenic mouse model, genetic knockout (IKKβ, TNFR1), in vivo LTbetaR blocking, histopathology","journal":"Cancer cell","confidence":"High","confidence_rationale":"Tier 2 — multiple genetic models with mechanistic epistasis and defined phenotypic readouts","pmids":["19800575"],"is_preprint":false},{"year":2016,"finding":"LIGHT activates LTBR signaling in tumors, leading to production of chemokines that recruit T cells; antibody-guided tumor targeting of LIGHT creates a T cell-inflamed microenvironment and overcomes resistance to PD-L1 checkpoint blockade, establishing LTBR signaling as a driver of T cell infiltration and anti-tumor immunity.","method":"Antibody-LIGHT fusion protein, in vivo tumor models, T cell infiltration analysis, combination immunotherapy","journal":"Cancer cell","confidence":"High","confidence_rationale":"Tier 2 — in vivo functional studies with defined cellular and molecular phenotypes","pmids":["26977880"],"is_preprint":false},{"year":2020,"finding":"LTbetaR signaling promotes non-canonical NF-κB activation and TGFβ signaling in lung epithelial cells, driving COPD pathology; therapeutic inhibition of LTbetaR disrupts inducible bronchus-associated lymphoid tissue (iBALT), prevents epithelial cell death, activates WNT/β-catenin signaling in alveolar epithelial progenitor cells, and induces lung tissue regeneration and reversion of airway fibrosis in mice.","method":"In vivo LTbetaR blocking in mouse models (young and aged, cigarette smoke-exposed), signaling pathway analysis, cell death assays, WNT reporter assays, patient tissue analysis","journal":"Nature","confidence":"High","confidence_rationale":"Tier 2 — in vivo therapeutic intervention with multiple mechanistic readouts, validated in both mouse models and human COPD tissue","pmids":["33149305"],"is_preprint":false},{"year":2022,"finding":"CREB1 transcriptionally activates LTBR expression in lung epithelial cells; LTBR mediates NF-κB pathway activation downstream of hyperoxia; silencing LTBR rescues hyperoxia-induced suppression of cell viability and promotion of apoptosis in A549 and ATII cells, establishing a CREB1/LTBR/NF-κB axis in bronchopulmonary dysplasia.","method":"Luciferase reporter assay, ChIP assay, siRNA knockdown, cell viability assay (CCK-8), flow cytometry apoptosis assay","journal":"Computational and mathematical methods in medicine","confidence":"Medium","confidence_rationale":"Tier 2 — ChIP and reporter assay confirm transcriptional regulation, plus functional KD phenotype; single lab","pmids":["36118831"],"is_preprint":false},{"year":2023,"finding":"TRAF5 interacts with LTBR in HCC cells (confirmed by co-immunoprecipitation and immunofluorescence); TRAF5 silencing downregulates LTBR expression and suppresses LTBR-mediated NF-κB signaling, enhancing necroptosis (phosphorylation of RIP1 and MLKL); LTBR overexpression rescues the pro-necroptotic and anti-proliferative effects of TRAF5 knockdown.","method":"Co-immunoprecipitation, immunofluorescence, siRNA knockdown, overexpression rescue, western blotting, xenograft model","journal":"PeerJ","confidence":"Medium","confidence_rationale":"Tier 2 — co-IP plus epistatic rescue experiment; single lab","pmids":["37366426"],"is_preprint":false},{"year":2024,"finding":"LTBR maintains immunosuppressive M2 phenotype of tumor-associated macrophages (TAMs) through non-canonical NF-κB and Wnt/β-catenin signaling pathways; macrophage-specific knockout of LTBR hinders tumor growth and prolongs survival in vivo by blocking TAM immunosuppressive activity; TAM-targeted LTBR siRNA delivery improves ICI therapeutic response.","method":"Macrophage-specific conditional knockout, siRNA delivery, in vivo tumor models, signaling pathway analysis, immunofluorescence, single-cell RNA-seq analysis","journal":"iMeta","confidence":"Medium","confidence_rationale":"Tier 2 — cell-type-specific KO with in vivo tumor phenotype and pathway analysis; single lab","pmids":["39429877"],"is_preprint":false},{"year":2024,"finding":"Lymphotoxin-beta (LTβ) ligand activates the LTBR/NIK/RelB non-canonical NF-κB axis in cholangiocarcinoma cells, promoting proliferation; NIK inhibitor B022 suppresses RelB expression in patient-derived CCA organoids and blocks nuclear co-translocation of RelB and p52 stimulated by LTα1/β2.","method":"LTα1/β2 stimulation, NIK small-molecule inhibitor, patient-derived organoids, real-time impedance measurement, immunoblot, RNA sequencing, in vivo murine CCA models","journal":"Liver international","confidence":"Medium","confidence_rationale":"Tier 2 — pharmacological inhibition with patient-derived organoids and in vivo models; single lab","pmids":["39164890"],"is_preprint":false},{"year":2013,"finding":"Recombinant rabbit TNFSF14 (OcsTNFSF14) and extracellular LTBR (OceLTBR) proteins bind splenic T cells in vitro, confirming that the TNFSF14-LTBR ligand-receptor interaction is conserved in Oryctolagus cuniculus.","method":"Recombinant protein expression, confocal laser microscopy binding assay, SDS-PAGE, Western blot","journal":"Molecular immunology","confidence":"Low","confidence_rationale":"Tier 3 — single binding assay in a model organism, limited mechanistic follow-up","pmids":["23370464"],"is_preprint":false},{"year":2026,"finding":"FAP-targeted LTBR agonist (FAP-LTBR) selectively activates endothelial cells via LTBR signaling in a FAP-dependent manner, inducing chemokine secretion, T cell adhesion and extravasation, HEV differentiation, TLS-like immune aggregate formation, and increased B and T cell (including stem-like TCF1+ CD8+) infiltration in murine tumor models.","method":"FAP-LTBR bispecific agonist, primary human endothelial cells, 3D microfluidic vascular models, multiple murine tumor models, spatial transcriptomics, 3D immunophenotyping","journal":"Clinical cancer research","confidence":"Medium","confidence_rationale":"Tier 2 — multiple orthogonal in vitro and in vivo methods with defined cellular/molecular phenotypes; single lab","pmids":["42012453"],"is_preprint":false},{"year":2025,"finding":"LTβR and IFN sensing pathways are necessary and sufficient for HLA class I-independent cancer cell lysis by CD8+ TIL; whole-genome CRISPR loss-of-function screen nominated LTBR as a key determinant of TIL-mediated killing; expanded CD8+ TIL express high LTB and upregulate LTA upon co-culture with cancer cells.","method":"Whole-genome CRISPR loss-of-function screen, patient-derived TIL-melanoma co-cultures, scRNA-seq, scTCR-seq, validation knockouts","journal":"bioRxiv","confidence":"Medium","confidence_rationale":"Tier 2 — genome-wide CRISPR screen with validation; preprint, not yet peer-reviewed","pmids":[],"is_preprint":true}],"current_model":"LTBR is a TNF receptor superfamily member that is activated by the LT-alpha1/beta2 heterotrimer and LIGHT (TNFSF14); upon ligation it recruits TRAF3 (mediating apoptosis) and TRAF5, activates both canonical (IKKβ/NEMO-dependent, driving proinflammatory genes) and non-canonical (NIK/IKKα-dependent, processing p100 to p52/RelB, driving lymphoid organogenesis chemokines) NF-κB pathways, and phosphorylates p65 at Ser536 via NIK/IKKα; in vivo, LTBR signaling is required for tertiary lymphoid structure formation, drives hepatitis-associated HCC via hepatocyte IKKβ, promotes M2 macrophage immunosuppression via non-canonical NF-κB and Wnt/β-catenin, and its inhibition activates WNT-driven lung regeneration, while its activation by tumor-targeted LIGHT or FAP-directed agonists remodels the tumor microenvironment to enhance T cell infiltration and immunotherapy efficacy."},"narrative":{"teleology":[{"year":1994,"claim":"Identifying the receptor for surface lymphotoxin established that LTα/LTβ heteromeric complexes signal through a dedicated receptor (LTBR) distinct from the TNF receptors that bind soluble LTα homotrimers, defining a new branch of TNF superfamily signaling.","evidence":"Receptor binding assays with purified LTα/LTβ heteromers","pmids":["8171323"],"confidence":"High","gaps":["Stoichiometry of the LTα/LTβ:LTBR complex not determined","Intracellular signaling mechanism unknown at this point"]},{"year":1997,"claim":"Mapping the adaptor recruitment profile of LTBR revealed that TRAF3 mediates LTBR-induced cell death while TRAF2 and TRAF5 contribute to NF-κB activation, establishing that LTBR bifurcates into independent death and transcriptional signaling arms through distinct TRAF proteins.","evidence":"Co-immunoprecipitation, dominant-negative TRAF3/TRAF5 mutants, NF-κB reporters, and cell death assays in multiple cell types","pmids":["7859281","8663299","9122217"],"confidence":"High","gaps":["Precise TRAF binding motifs on the LTBR cytoplasmic tail not resolved","Whether other adaptors participate in either arm remained open"]},{"year":1998,"claim":"Discovery that LIGHT (TNFSF14) is a second ligand for LTBR, independent of LTα/LTβ, expanded the receptor's functional repertoire and revealed regulation by decoy receptor DcR3, providing a framework for how LTBR signaling is tuned by ligand competition.","evidence":"Receptor-ligand binding assays, functional blocking, cytotoxicity assays with recombinant LIGHT and DcR3","pmids":["9462508","10318773","10799510"],"confidence":"High","gaps":["Relative physiological contribution of LIGHT versus LTα1β2 in different tissues unclear","Structural basis of ligand selectivity not determined"]},{"year":2002,"claim":"Demonstrating that LTBR activates two mechanistically distinct NF-κB pathways—canonical IKKβ/NEMO-dependent (proinflammatory genes) and non-canonical NIK/IKKα-dependent (p100→p52 processing, lymphoid chemokines)—with an additional NIK/IKKα-mediated p65-Ser536 phosphorylation step, resolved how a single receptor drives both acute inflammation and lymphoid organogenesis programs.","evidence":"Genetic epistasis in IKK-deficient MEFs, dominant-negative kinases, site-directed mutagenesis of p65-Ser536, chemokine expression profiling","pmids":["12387745","12419817"],"confidence":"High","gaps":["Temporal kinetics of the two pathways in vivo not resolved","Contribution of p65-Ser536 phosphorylation versus p52/RelB to specific gene targets uncharacterized"]},{"year":2006,"claim":"Showing that LTBR signaling is necessary and sufficient for tertiary lymphoid organ (TLO) formation in vivo linked the non-canonical NF-κB chemokine program to organized ectopic lymphoid tissue development and autoimmune pathology.","evidence":"In vivo LIGHT blockade and islet-specific LIGHT transgenic mice in NOD diabetes model","pmids":["16934497"],"confidence":"High","gaps":["Cell-type-specific contributions of stromal versus immune LTBR in TLO maintenance not dissected","Signals distinguishing protective versus pathogenic TLOs unknown"]},{"year":2009,"claim":"Establishing that chronic hepatic LTα/LTβ–LTBR signaling drives HCC through hepatocyte IKKβ, independent of TNFR1, identified LTBR as a direct oncogenic driver in inflammation-associated liver cancer.","evidence":"Liver-specific LTαβ transgenic mice, IKKβ and TNFR1 genetic knockouts, in vivo LTβR blockade","pmids":["19800575"],"confidence":"High","gaps":["Downstream IKKβ target genes mediating hepatocyte transformation not fully catalogued","Whether LTBR blockade can reverse established HCC not tested"]},{"year":2016,"claim":"Tumor-targeted delivery of LIGHT demonstrated that activating LTBR signaling in the tumor stroma generates T cell-recruiting chemokines sufficient to overcome checkpoint blockade resistance, establishing LTBR agonism as a strategy for converting immune-cold tumors.","evidence":"Antibody-LIGHT fusion protein in syngeneic tumor models with combination anti-PD-L1 therapy","pmids":["26977880"],"confidence":"High","gaps":["Relative contribution of LTBR versus HVEM to LIGHT-mediated immune remodeling in tumors not separated","Optimal LTBR engagement thresholds for efficacy versus toxicity unknown"]},{"year":2020,"claim":"Demonstrating that LTBR blockade disrupts pathogenic iBALT, suppresses non-canonical NF-κB/TGFβ, and activates WNT/β-catenin-driven lung regeneration revealed LTBR as a therapeutic target in COPD and established a previously unrecognized connection between lymphotoxin signaling and epithelial progenitor cell fate.","evidence":"In vivo LTβR blocking in aged and cigarette-smoke-exposed mice, WNT reporter assays, validation in human COPD tissue","pmids":["33149305"],"confidence":"High","gaps":["Mechanism by which LTBR suppresses WNT signaling not molecularly defined","Long-term safety of LTBR blockade for regenerative therapy not assessed"]},{"year":2024,"claim":"Cell-type-specific studies revealed that LTBR maintains immunosuppressive M2 macrophage polarization via non-canonical NF-κB/Wnt/β-catenin and that FAP-targeted LTBR agonism selectively activates endothelial cells to form TLS-like aggregates, refining the understanding of how LTBR controls different immune–stromal compartments in the tumor microenvironment.","evidence":"Macrophage-specific conditional LTBR knockout, TAM-targeted siRNA delivery, FAP-LTBR bispecific agonist in 3D microfluidic models and murine tumors, spatial transcriptomics","pmids":["39429877","42012453","39164890"],"confidence":"Medium","gaps":["How LTBR agonism and antagonism in different cell types can be simultaneously exploited therapeutically is unresolved","Whether macrophage LTBR signaling is relevant in non-tumor inflammatory settings not tested","Findings from single labs await independent replication"]},{"year":null,"claim":"Unresolved: the structural basis of LTBR signal complex assembly (TRAF stoichiometry, conformational activation), the precise molecular mechanism linking LTBR to WNT/β-catenin suppression, and the determinants separating protective (anti-tumor TLS) from pathogenic (autoimmune TLO, HCC-promoting) outcomes of LTBR signaling remain undefined.","evidence":"","pmids":[],"confidence":"Low","gaps":["No crystal or cryo-EM structure of LTBR signaling complex","Molecular intermediates between LTBR and WNT pathway not identified","Context-dependent rules governing beneficial versus harmful LTBR activation not established"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0060089","term_label":"molecular transducer activity","supporting_discovery_ids":[0,5,7]},{"term_id":"GO:0060090","term_label":"molecular adaptor activity","supporting_discovery_ids":[1,2,3]}],"localization":[{"term_id":"GO:0005886","term_label":"plasma membrane","supporting_discovery_ids":[0,1,5,7]}],"pathway":[{"term_id":"GO:0005886","term_label":"plasma membrane","supporting_discovery_ids":[0]},{"term_id":"R-HSA-162582","term_label":"Signal Transduction","supporting_discovery_ids":[2,3,8,9,14,15,17]},{"term_id":"R-HSA-168256","term_label":"Immune System","supporting_discovery_ids":[10,12,16,19]},{"term_id":"R-HSA-5357801","term_label":"Programmed Cell Death","supporting_discovery_ids":[3,6,7,15]},{"term_id":"R-HSA-1643685","term_label":"Disease","supporting_discovery_ids":[11,17]}],"complexes":[],"partners":["TRAF3","TRAF5","TRAF2","TRAF1","TNFSF14","LTA","LTB","TNFRSF6B"],"other_free_text":[]},"mechanistic_narrative":"LTBR (lymphotoxin-beta receptor / TNFRSF3) is a TNF receptor superfamily member that transduces signals from the LTα1β2 heterotrimer and LIGHT (TNFSF14) to orchestrate lymphoid tissue organization, inflammatory gene expression, and cell death [PMID:8171323, PMID:9462508]. Upon ligand engagement, LTBR recruits TRAF3 to propagate apoptotic signaling and TRAF2/TRAF5 to activate two distinct NF-κB arms: a canonical IKKβ/NEMO-dependent pathway driving proinflammatory genes and a non-canonical NIK/IKKα-dependent pathway that processes p100 to p52/RelB and induces lymphoid organogenesis chemokines, with NIK/IKKα also phosphorylating p65 at Ser536 to enhance transcriptional activation [PMID:9122217, PMID:8663299, PMID:12387745, PMID:12419817]. In vivo, LTBR signaling is required for tertiary lymphoid structure formation and maintenance, drives hepatitis-associated hepatocellular carcinoma through hepatocyte IKKβ, sustains immunosuppressive M2 macrophage polarization via non-canonical NF-κB and Wnt/β-catenin, and—when activated by tumor-targeted LIGHT or FAP-directed agonists—remodels the tumor microenvironment to promote T cell infiltration and enhance immunotherapy efficacy [PMID:16934497, PMID:19800575, PMID:39429877, PMID:26977880, PMID:42012453]. Therapeutic blockade of LTBR in lung tissue disrupts inducible bronchus-associated lymphoid tissue and activates WNT/β-catenin-driven alveolar regeneration, reversing airway fibrosis in COPD models [PMID:33149305]."},"prefetch_data":{"uniprot":{"accession":"P36941","full_name":"Tumor necrosis factor receptor superfamily member 3","aliases":["Lymphotoxin-beta receptor","Tumor necrosis factor C receptor","Tumor necrosis factor receptor 2-related protein","Tumor necrosis factor receptor type III","TNF-RIII","TNFR-III"],"length_aa":435,"mass_kda":46.7,"function":"Receptor for the heterotrimeric lymphotoxin containing LTA and LTB, and for TNFS14/LIGHT (PubMed:24248355). Activates NF-kappa-B signaling pathway upon stimulation with lymphotoxin (LTA(1)-LTB(2)) (PubMed:24248355). Promotes apoptosis via TRAF3 and TRAF5. May play a role in the development of lymphoid organs","subcellular_location":"Membrane","url":"https://www.uniprot.org/uniprotkb/P36941/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/LTBR","classification":"Not Classified","n_dependent_lines":1,"n_total_lines":1208,"dependency_fraction":0.0008278145695364238},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[],"url":"https://opencell.sf.czbiohub.org/search/LTBR","total_profiled":1310},"omim":[{"mim_id":"619289","title":"ZINC FINGER PROTEIN 91, ATYPICAL E3 UBIQUITIN LIGASE; ZFP91","url":"https://www.omim.org/entry/619289"},{"mim_id":"611211","title":"RECEPTOR EXPRESSED IN LYMPHOID TISSUES; RELT","url":"https://www.omim.org/entry/611211"},{"mim_id":"610562","title":"ZINC FINGER CCCH DOMAIN-CONTAINING PROTEIN 12A; ZC3H12A","url":"https://www.omim.org/entry/610562"},{"mim_id":"607414","title":"FEZ FAMILY ZINC FINGER PROTEIN 2; FEZF2","url":"https://www.omim.org/entry/607414"},{"mim_id":"607358","title":"AUTOIMMUNE REGULATOR; AIRE","url":"https://www.omim.org/entry/607358"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Supported","locations":[{"location":"Golgi apparatus","reliability":"Supported"}],"tissue_specificity":"Low tissue specificity","tissue_distribution":"Detected in all","driving_tissues":[],"url":"https://www.proteinatlas.org/search/LTBR"},"hgnc":{"alias_symbol":["TNFCR","TNFR-RP","TNFR2-RP","TNF-R-III","TNFRSF3"],"prev_symbol":["D12S370"]},"alphafold":{"accession":"P36941","domains":[{"cath_id":"2.10.50.10","chopping":"33-101","consensus_level":"medium","plddt":94.8499,"start":33,"end":101},{"cath_id":"2.10.50.10","chopping":"103-145","consensus_level":"medium","plddt":84.643,"start":103,"end":145},{"cath_id":"2.10.50.10","chopping":"148-215","consensus_level":"medium","plddt":84.9813,"start":148,"end":215}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/P36941","model_url":"https://alphafold.ebi.ac.uk/files/AF-P36941-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-P36941-F1-predicted_aligned_error_v6.png","plddt_mean":66.56},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=LTBR","jax_strain_url":"https://www.jax.org/strain/search?query=LTBR"},"sequence":{"accession":"P36941","fasta_url":"https://rest.uniprot.org/uniprotkb/P36941.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/P36941/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/P36941"}},"corpus_meta":[{"pmid":"15811637","id":"PMC_15811637","title":"Muscle atrophy and bone loss after 90 days' bed rest and the effects of flywheel resistive exercise and pamidronate: results from the LTBR study.","date":"2005","source":"Bone","url":"https://pubmed.ncbi.nlm.nih.gov/15811637","citation_count":219,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"17259312","id":"PMC_17259312","title":"The IclR-type transcriptional repressor LtbR regulates the expression of leucine and tryptophan biosynthesis genes in the amino acid producer Corynebacterium glutamicum.","date":"2007","source":"Journal of bacteriology","url":"https://pubmed.ncbi.nlm.nih.gov/17259312","citation_count":42,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"39429877","id":"PMC_39429877","title":"LTBR acts as a novel immune checkpoint of tumor-associated macrophages for cancer 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understanding of the protein interaction network of the human liver.","date":"2011","source":"Molecular systems biology","url":"https://pubmed.ncbi.nlm.nih.gov/21988832","citation_count":207,"is_preprint":false,"source_track":"gene2pubmed"},{"pmid":"8995654","id":"PMC_8995654","title":"Hepatitis C virus core protein interacts with the cytoplasmic tail of lymphotoxin-beta receptor.","date":"1997","source":"Journal of virology","url":"https://pubmed.ncbi.nlm.nih.gov/8995654","citation_count":188,"is_preprint":false,"source_track":"gene2pubmed"},{"pmid":"10799510","id":"PMC_10799510","title":"The lymphotoxin-beta receptor is necessary and sufficient for LIGHT-mediated apoptosis of tumor cells.","date":"2000","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/10799510","citation_count":178,"is_preprint":false,"source_track":"gene2pubmed"},{"pmid":"11279055","id":"PMC_11279055","title":"A diverse family of proteins containing tumor necrosis factor 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lung.","date":"2020","source":"Nature","url":"https://pubmed.ncbi.nlm.nih.gov/33149305","citation_count":141,"is_preprint":false,"source_track":"gene2pubmed"}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":8649,"output_tokens":1814,"usd":0.026579},"stage2":{"model":"claude-opus-4-6","input_tokens":5162,"output_tokens":2391,"usd":0.128378},"total_usd":0.406583,"stage1_batch_id":"msgbatch_01Mgbec4vM6c9vXht7JVJzss","stage2_batch_id":"msgbatch_01JkuuH5RB2BdJNsgnhjbC6s","note":"batch pricing = 50% of standard","round2_stage1":{"model":"claude-sonnet-4-6","input_tokens":21511,"output_tokens":5217,"usd":0.071394},"round2_rules_fired":"R3","round2_stage2":{"model":"claude-opus-4-6","input_tokens":9096,"output_tokens":2987,"usd":0.180232}},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2024,\n      \"finding\": \"LTBR maintains immunosuppressive activity and M2 phenotype of tumor-associated macrophages (TAMs) via noncanonical NF-κB and Wnt/β-catenin signaling pathways; macrophage-specific knockout of LTBR blocks TAM immunosuppressive activity and hinders tumor growth.\",\n      \"method\": \"Macrophage-specific LTBR knockout mouse model, flow cytometry, in vitro macrophage polarization assays, signaling pathway analysis\",\n      \"journal\": \"iMeta\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — clean KO with defined cellular phenotype and pathway placement, single lab\",\n      \"pmids\": [\"39429877\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"CREB1 directly transcriptionally activates LTBR expression; LTBR in turn activates the NF-κB pathway to regulate apoptosis and viability of lung epithelial cells under hyperoxic stress.\",\n      \"method\": \"Luciferase reporter assay, ChIP assay, siRNA knockdown, flow cytometry, CCK-8 assay\",\n      \"journal\": \"Computational and mathematical methods in medicine\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — luciferase and ChIP confirm direct transcription factor binding; KD shows functional consequence; single lab\",\n      \"pmids\": [\"36118831\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"Lymphotoxin-β (LTβ) ligand activates LTBR, which signals through NIK (NF-κB-inducing kinase) to activate the transcription factor RelB (noncanonical NF-κB pathway), driving proliferation in cholangiocarcinoma cells and organoids.\",\n      \"method\": \"LTα1/β2 stimulation of CCA cell lines and patient-derived organoids, NIK inhibitor (B022), immunoblot, qRT-PCR, RNA sequencing, real-time impedance measurement, in vivo CCA models\",\n      \"journal\": \"Liver international\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 — multiple orthogonal methods (pharmacological inhibition, organoids, in vivo models), clear pathway ordering (LTβ→LTBR→NIK→RelB)\",\n      \"pmids\": [\"39164890\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"TRAF5 physically interacts with LTBR and positively regulates its expression; TRAF5 knockdown suppresses LTBR-mediated NF-κB signaling, thereby promoting necroptosis (via RIP1/MLKL phosphorylation) in hepatocellular carcinoma cells.\",\n      \"method\": \"Co-immunoprecipitation, immunofluorescence, siRNA knockdown, western blotting (p-RIP1, p-MLKL), flow cytometry, xenograft model\",\n      \"journal\": \"PeerJ\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — reciprocal Co-IP confirms TRAF5-LTBR interaction; rescue experiment (LTBR OE reverses TRAF5 KD phenotype) places LTBR downstream of TRAF5; single lab\",\n      \"pmids\": [\"37366426\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2026,\n      \"finding\": \"Targeted activation of LTBR signaling in FAP-expressing tumor stroma drives high endothelial venule (HEV) differentiation and tertiary lymphoid structure formation, enhances T cell adhesion and extravasation, and promotes broad immune infiltration into tumors.\",\n      \"method\": \"FAP-LTBR agonist fusion protein, primary human endothelial cells, 3D microfluidic vascular models, multiple murine tumor models, spatial transcriptomics, 3D immunophenotyping, combination with CPIs/T cell engagers\",\n      \"journal\": \"Clinical cancer research\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 — multiple orthogonal in vitro and in vivo models with spatial transcriptomics; engineered agonist directly probes LTBR function; single study but broad methodology\",\n      \"pmids\": [\"42012453\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"LTβR signaling on cancer cells is necessary and sufficient for class I HLA-independent lysis by CD8+ TIL; dual LTβR and IFN sensing is required for TIL-mediated cancer cell killing, with expanded CD8+ TIL expressing high LTB and upregulating LTA upon co-culture with cancer cells.\",\n      \"method\": \"Whole-genome loss-of-function CRISPR screen, patient-derived TIL-melanoma co-cultures, scRNA-seq, scTCR-seq, functional validation of LTβR pathway\",\n      \"journal\": \"bioRxiv\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 1-2 — CRISPR screen with functional validation; multiple orthogonal methods; preprint, not yet peer-reviewed\",\n      \"pmids\": [\"bio_10.1101_2025.11.19.689204\"],\n      \"is_preprint\": true\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"Rabbit LTBR extracellular domain protein binds TNFSF14 (LIGHT) and the complex binds splenic T cells in vitro, confirming receptor-ligand interaction at the cell surface.\",\n      \"method\": \"Recombinant protein production, Ni-NTA affinity chromatography, confocal laser microscopy binding assay\",\n      \"journal\": \"Molecular immunology\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 — single binding assay in rabbit ortholog model, no functional pathway dissection\",\n      \"pmids\": [\"23370464\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"LTBR (lymphotoxin-β receptor) is a TNF receptor superfamily member that, upon binding by lymphotoxin-β (LTα1β2) or LIGHT (TNFSF14), signals primarily through the noncanonical NF-κB pathway (via NIK→RelB/p52) and is also coupled to canonical NF-κB; it physically associates with TRAF5 (which sustains LTBR expression and NF-κB activation), is transcriptionally induced by CREB1, mediates HEV differentiation and tertiary lymphoid structure formation in tumor stroma, maintains TAM immunosuppressive/M2 identity via noncanonical NF-κB and Wnt/β-catenin, and on cancer cells serves as the target for LTβ-expressing CD8+ TIL-mediated HLA-independent cytotoxicity.\"\n}\n```\n\n--- ROUND 2 (R2/R3, augmented corpus) ---\n\n```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 1994,\n      \"finding\": \"Identification of LTBR (lymphotoxin-beta receptor) as a receptor specific for the LT-alpha/LT-beta heteromeric complex on the cell surface, distinct from the p60 and p80 TNF receptors that bind secreted LT-alpha homotrimers.\",\n      \"method\": \"Receptor binding assay / protein biochemistry\",\n      \"journal\": \"Science\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 — original identification paper, foundational discovery replicated across the field\",\n      \"pmids\": [\"8171323\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1995,\n      \"finding\": \"TRAF2 (LAP1) and TRAF1 (EBI6) associate with the cytoplasmic domain of LTBR; EBV LMP1 co-immunoprecipitates with these TRAF proteins and causes them to localize to LMP1 clusters in the plasma membrane, linking LMP1 transformation to TNFR-family signaling including LTBR.\",\n      \"method\": \"Co-immunoprecipitation, immunofluorescence localization\",\n      \"journal\": \"Cell\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — reciprocal co-IP with functional localization, highly cited foundational paper\",\n      \"pmids\": [\"7859281\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1996,\n      \"finding\": \"TRAF5 binds specifically to the cytoplasmic region of LTBR (but not CD40, TNFR1, TNFR2, Fas, or NGFR) in vitro and co-immunoprecipitates with LTBR when overexpressed in COS7 cells; TRAF5 overexpression activates NF-κB and a dominant-negative truncated TRAF5 partially inhibits LTbetaR-induced NF-κB activation.\",\n      \"method\": \"In vitro translation binding assay, co-immunoprecipitation in COS7 cells, NF-κB reporter assay\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — multiple orthogonal methods (pull-down, co-IP, functional reporter), highly cited\",\n      \"pmids\": [\"8663299\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1997,\n      \"finding\": \"TRAF3 is rapidly recruited to the LTBR cytoplasmic domain upon LT-alpha1/beta2 or agonistic anti-LTBR antibody treatment; dominant-negative TRAF3 (lacking RING and zinc finger domains) specifically inhibits LTBR-mediated cell death but not NF-κB activation, establishing TRAF3 as a critical component of the LTBR death-signaling complex and demonstrating two independent signaling pathways downstream of LTBR.\",\n      \"method\": \"Co-immunoprecipitation, stable overexpression of dominant-negative mutant, cell death assay\",\n      \"journal\": \"Proceedings of the National Academy of Sciences of the United States of America\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — reciprocal co-IP plus dominant-negative epistasis with specific phenotypic readout\",\n      \"pmids\": [\"9122217\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1997,\n      \"finding\": \"HCV core protein directly binds the cytoplasmic tail of LTBR; the binding site on LTBR was mapped to a 58-amino-acid region of its cytoplasmic tail and the HCV core binding site was localized to residues 36–91 (hydrophilic region); association was confirmed in mammalian cells by co-immunoprecipitation.\",\n      \"method\": \"Yeast two-hybrid screen, GST pull-down assay, protein-protein blotting, mammalian co-immunoprecipitation\",\n      \"journal\": \"Journal of virology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 — multiple orthogonal methods including in vitro reconstitution and mammalian co-IP, domain mapping\",\n      \"pmids\": [\"8995654\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1998,\n      \"finding\": \"LIGHT (TNFSF14), a new TNF superfamily member produced by activated T cells, binds both HVEM and LTBR (the LT-alpha/beta heterotrimer receptor); LIGHT does not form complexes with LT-alpha or LT-beta and HSV gD inhibits HVEM-LIGHT interaction, establishing LIGHT as a dual-receptor ligand in the lymphotoxin system.\",\n      \"method\": \"Receptor-ligand binding assays, transfection, functional blocking studies\",\n      \"journal\": \"Immunity\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — multiple binding and functional assays; highly cited foundational paper\",\n      \"pmids\": [\"9462508\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1999,\n      \"finding\": \"Decoy receptor 3 (TR6/DcR3) specifically binds LIGHT and FasL; TR6 inhibits LIGHT-induced cytotoxicity by blocking LIGHT interactions with both LTBR and HVEM, suppressing LIGHT-mediated apoptosis in HT29 cells that express both receptors.\",\n      \"method\": \"Immunoprecipitation of recombinant proteins, flow cytometry, cytotoxicity assay\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — multiple assays demonstrating receptor competition and functional consequence\",\n      \"pmids\": [\"10318773\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2000,\n      \"finding\": \"LTBR (not HVEM) is necessary and sufficient for LIGHT-mediated apoptosis and ICAM-1 induction; LIGHT mutants with selective HveA binding cannot trigger cell death; LTBR (not HveA) recruits TRAF3, and dominant-negative TRAF3 blocks LIGHT-induced death, establishing TRAF3 recruitment as the mechanism propagating LTBR death signals.\",\n      \"method\": \"Point mutagenesis of LIGHT, receptor-specific antibody blocking, dominant-negative TRAF3 overexpression, cell death assay\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 — mutagenesis of ligand, receptor-specific blocking antibodies, epistasis via dominant-negative, multiple orthogonal methods\",\n      \"pmids\": [\"10799510\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2002,\n      \"finding\": \"LTBR ligation activates two distinct NF-κB pathways: (1) canonical IKKβ/NEMO-dependent NF-κB driving proinflammatory genes (VCAM-1, MIP-1β, MIP-2) and expression of p100; (2) non-canonical NIK/IKKα-dependent processing of NF-κB2/p100 to p52 (independent of NEMO/IKKγ), driving lymphoid organogenesis chemokines (SLC, BLC, ELC, SDF1, BAFF).\",\n      \"method\": \"Genetic epistasis using IKK-deficient cells, dominant-negative kinase mutants, NF-κB reporter assays, chemokine/cytokine expression analysis\",\n      \"journal\": \"Immunity\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 — multiple genetic loss-of-function models with specific gene expression readouts; highly cited definitive pathway paper\",\n      \"pmids\": [\"12387745\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2002,\n      \"finding\": \"NIK and IKKα mediate LTBR-induced NF-κB activation through phosphorylation of the p65 subunit at serine 536 in its transactivation domain 1 (TA1); this phosphorylation is required for transcriptional activation without altering IκB phosphorylation levels or p65 nuclear localization, revealing a distinct mechanism for LTBR-driven NF-κB activity.\",\n      \"method\": \"Dominant-negative kinase mutants (NIK, IKKα), Gal4-fusion transactivation reporter assay, site-directed mutagenesis of p65-Ser536, phosphorylation detection following LTbetaR stimulation\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 — mutagenesis, phosphorylation detection, and heterologous reporter assay demonstrating mechanism\",\n      \"pmids\": [\"12419817\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2006,\n      \"finding\": \"LTBR signaling controls the development and maintenance of tertiary lymphoid organs (TLO) in the pancreas; blockade of TNFSF14 (LIGHT) signaling reduces LTBR-controlled migration factor expression and disrupts TLO organization, preventing diabetes in NOD mice; transgenic TNFSF14 expression in islets rapidly promotes TLO formation even without draining lymph nodes.\",\n      \"method\": \"In vivo blockade of TNFSF14, transgenic mouse model, gene expression analysis, histology\",\n      \"journal\": \"Immunity\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — genetic gain- and loss-of-function in vivo with defined cellular and molecular phenotypes\",\n      \"pmids\": [\"16934497\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2009,\n      \"finding\": \"Hepatic LT-alpha/LT-beta overexpression drives liver inflammation and HCC in mice; HCC development depends on lymphocytes and hepatocyte IKKβ but not TNFR1; in vivo LTbetaR stimulation implicates hepatocytes as the major LT-responsive liver cells; LTbetaR inhibition suppresses HCC formation in LT-transgenic mice with hepatitis.\",\n      \"method\": \"Liver-specific LTalphabeta transgenic mouse model, genetic knockout (IKKβ, TNFR1), in vivo LTbetaR blocking, histopathology\",\n      \"journal\": \"Cancer cell\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — multiple genetic models with mechanistic epistasis and defined phenotypic readouts\",\n      \"pmids\": [\"19800575\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"LIGHT activates LTBR signaling in tumors, leading to production of chemokines that recruit T cells; antibody-guided tumor targeting of LIGHT creates a T cell-inflamed microenvironment and overcomes resistance to PD-L1 checkpoint blockade, establishing LTBR signaling as a driver of T cell infiltration and anti-tumor immunity.\",\n      \"method\": \"Antibody-LIGHT fusion protein, in vivo tumor models, T cell infiltration analysis, combination immunotherapy\",\n      \"journal\": \"Cancer cell\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — in vivo functional studies with defined cellular and molecular phenotypes\",\n      \"pmids\": [\"26977880\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"LTbetaR signaling promotes non-canonical NF-κB activation and TGFβ signaling in lung epithelial cells, driving COPD pathology; therapeutic inhibition of LTbetaR disrupts inducible bronchus-associated lymphoid tissue (iBALT), prevents epithelial cell death, activates WNT/β-catenin signaling in alveolar epithelial progenitor cells, and induces lung tissue regeneration and reversion of airway fibrosis in mice.\",\n      \"method\": \"In vivo LTbetaR blocking in mouse models (young and aged, cigarette smoke-exposed), signaling pathway analysis, cell death assays, WNT reporter assays, patient tissue analysis\",\n      \"journal\": \"Nature\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — in vivo therapeutic intervention with multiple mechanistic readouts, validated in both mouse models and human COPD tissue\",\n      \"pmids\": [\"33149305\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"CREB1 transcriptionally activates LTBR expression in lung epithelial cells; LTBR mediates NF-κB pathway activation downstream of hyperoxia; silencing LTBR rescues hyperoxia-induced suppression of cell viability and promotion of apoptosis in A549 and ATII cells, establishing a CREB1/LTBR/NF-κB axis in bronchopulmonary dysplasia.\",\n      \"method\": \"Luciferase reporter assay, ChIP assay, siRNA knockdown, cell viability assay (CCK-8), flow cytometry apoptosis assay\",\n      \"journal\": \"Computational and mathematical methods in medicine\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — ChIP and reporter assay confirm transcriptional regulation, plus functional KD phenotype; single lab\",\n      \"pmids\": [\"36118831\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"TRAF5 interacts with LTBR in HCC cells (confirmed by co-immunoprecipitation and immunofluorescence); TRAF5 silencing downregulates LTBR expression and suppresses LTBR-mediated NF-κB signaling, enhancing necroptosis (phosphorylation of RIP1 and MLKL); LTBR overexpression rescues the pro-necroptotic and anti-proliferative effects of TRAF5 knockdown.\",\n      \"method\": \"Co-immunoprecipitation, immunofluorescence, siRNA knockdown, overexpression rescue, western blotting, xenograft model\",\n      \"journal\": \"PeerJ\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — co-IP plus epistatic rescue experiment; single lab\",\n      \"pmids\": [\"37366426\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"LTBR maintains immunosuppressive M2 phenotype of tumor-associated macrophages (TAMs) through non-canonical NF-κB and Wnt/β-catenin signaling pathways; macrophage-specific knockout of LTBR hinders tumor growth and prolongs survival in vivo by blocking TAM immunosuppressive activity; TAM-targeted LTBR siRNA delivery improves ICI therapeutic response.\",\n      \"method\": \"Macrophage-specific conditional knockout, siRNA delivery, in vivo tumor models, signaling pathway analysis, immunofluorescence, single-cell RNA-seq analysis\",\n      \"journal\": \"iMeta\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — cell-type-specific KO with in vivo tumor phenotype and pathway analysis; single lab\",\n      \"pmids\": [\"39429877\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"Lymphotoxin-beta (LTβ) ligand activates the LTBR/NIK/RelB non-canonical NF-κB axis in cholangiocarcinoma cells, promoting proliferation; NIK inhibitor B022 suppresses RelB expression in patient-derived CCA organoids and blocks nuclear co-translocation of RelB and p52 stimulated by LTα1/β2.\",\n      \"method\": \"LTα1/β2 stimulation, NIK small-molecule inhibitor, patient-derived organoids, real-time impedance measurement, immunoblot, RNA sequencing, in vivo murine CCA models\",\n      \"journal\": \"Liver international\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — pharmacological inhibition with patient-derived organoids and in vivo models; single lab\",\n      \"pmids\": [\"39164890\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"Recombinant rabbit TNFSF14 (OcsTNFSF14) and extracellular LTBR (OceLTBR) proteins bind splenic T cells in vitro, confirming that the TNFSF14-LTBR ligand-receptor interaction is conserved in Oryctolagus cuniculus.\",\n      \"method\": \"Recombinant protein expression, confocal laser microscopy binding assay, SDS-PAGE, Western blot\",\n      \"journal\": \"Molecular immunology\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 — single binding assay in a model organism, limited mechanistic follow-up\",\n      \"pmids\": [\"23370464\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2026,\n      \"finding\": \"FAP-targeted LTBR agonist (FAP-LTBR) selectively activates endothelial cells via LTBR signaling in a FAP-dependent manner, inducing chemokine secretion, T cell adhesion and extravasation, HEV differentiation, TLS-like immune aggregate formation, and increased B and T cell (including stem-like TCF1+ CD8+) infiltration in murine tumor models.\",\n      \"method\": \"FAP-LTBR bispecific agonist, primary human endothelial cells, 3D microfluidic vascular models, multiple murine tumor models, spatial transcriptomics, 3D immunophenotyping\",\n      \"journal\": \"Clinical cancer research\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — multiple orthogonal in vitro and in vivo methods with defined cellular/molecular phenotypes; single lab\",\n      \"pmids\": [\"42012453\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"LTβR and IFN sensing pathways are necessary and sufficient for HLA class I-independent cancer cell lysis by CD8+ TIL; whole-genome CRISPR loss-of-function screen nominated LTBR as a key determinant of TIL-mediated killing; expanded CD8+ TIL express high LTB and upregulate LTA upon co-culture with cancer cells.\",\n      \"method\": \"Whole-genome CRISPR loss-of-function screen, patient-derived TIL-melanoma co-cultures, scRNA-seq, scTCR-seq, validation knockouts\",\n      \"journal\": \"bioRxiv\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — genome-wide CRISPR screen with validation; preprint, not yet peer-reviewed\",\n      \"pmids\": [],\n      \"is_preprint\": true\n    }\n  ],\n  \"current_model\": \"LTBR is a TNF receptor superfamily member that is activated by the LT-alpha1/beta2 heterotrimer and LIGHT (TNFSF14); upon ligation it recruits TRAF3 (mediating apoptosis) and TRAF5, activates both canonical (IKKβ/NEMO-dependent, driving proinflammatory genes) and non-canonical (NIK/IKKα-dependent, processing p100 to p52/RelB, driving lymphoid organogenesis chemokines) NF-κB pathways, and phosphorylates p65 at Ser536 via NIK/IKKα; in vivo, LTBR signaling is required for tertiary lymphoid structure formation, drives hepatitis-associated HCC via hepatocyte IKKβ, promotes M2 macrophage immunosuppression via non-canonical NF-κB and Wnt/β-catenin, and its inhibition activates WNT-driven lung regeneration, while its activation by tumor-targeted LIGHT or FAP-directed agonists remodels the tumor microenvironment to enhance T cell infiltration and immunotherapy efficacy.\"\n}\n```","stage2_raw":"```json\n{\n  \"mechanistic_narrative\": \"LTBR (lymphotoxin-β receptor) is a TNF receptor superfamily member that transduces signals from lymphotoxin-α1β2 and LIGHT (TNFSF14) primarily through the noncanonical NF-κB pathway (NIK→RelB/p52), and also engages canonical NF-κB signaling, to regulate immune cell trafficking, lymphoid organogenesis, cell survival, and tumor microenvironment remodeling [PMID:39164890, PMID:42012453]. LTBR physically associates with TRAF5, which sustains LTBR expression and NF-κB activation; loss of TRAF5 shifts LTBR-dependent signaling toward necroptosis via RIP1/MLKL phosphorylation [PMID:37366426]. In the tumor stroma, targeted LTBR activation drives high endothelial venule differentiation and tertiary lymphoid structure formation, enhancing T cell infiltration, while in tumor-associated macrophages LTBR maintains immunosuppressive M2 polarization through noncanonical NF-κB and Wnt/β-catenin pathways [PMID:42012453, PMID:39429877]. CREB1 directly activates LTBR transcription, coupling stress-responsive signaling to LTBR-mediated NF-κB-dependent regulation of apoptosis [PMID:36118831].\",\n  \"teleology\": [\n    {\n      \"year\": 2013,\n      \"claim\": \"Early biochemical work confirmed that the LTBR extracellular domain directly engages TNFSF14 (LIGHT) at the cell surface, establishing LIGHT as a bona fide LTBR ligand beyond the canonical lymphotoxin-α1β2 heteromer.\",\n      \"evidence\": \"Recombinant rabbit LTBR ectodomain–LIGHT binding assay with confocal microscopy on splenic T cells\",\n      \"pmids\": [\"23370464\"],\n      \"confidence\": \"Low\",\n      \"gaps\": [\n        \"Single binding assay in a rabbit ortholog without functional pathway readout\",\n        \"No measurement of signaling consequences of LIGHT–LTBR engagement\",\n        \"Quantitative binding affinity not determined\"\n      ]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"Identification of CREB1 as a direct transcriptional activator of LTBR linked stress-responsive transcription factor activity to the receptor's expression level and downstream NF-κB-dependent control of cell viability.\",\n      \"evidence\": \"ChIP and luciferase reporter assays in lung epithelial cells under hyperoxia, with siRNA knockdown confirming functional dependence\",\n      \"pmids\": [\"36118831\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Whether CREB1-driven LTBR transcription operates in immune and stromal cells beyond lung epithelium is unknown\",\n        \"Other transcription factors regulating LTBR expression remain uncharacterized\"\n      ]\n    },\n    {\n      \"year\": 2023,\n      \"claim\": \"Demonstration that TRAF5 physically associates with LTBR and sustains its expression resolved how adapter stoichiometry controls the switch between NF-κB-dependent survival and necroptosis.\",\n      \"evidence\": \"Reciprocal co-immunoprecipitation, TRAF5 siRNA knockdown with p-RIP1/p-MLKL immunoblot, and LTBR overexpression rescue in hepatocellular carcinoma cells and xenografts\",\n      \"pmids\": [\"37366426\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Whether other TRAF family members compete for LTBR binding is untested\",\n        \"Structural basis of the TRAF5–LTBR interaction is unresolved\",\n        \"Necroptosis switch has been shown in HCC only; generality across tissues is unknown\"\n      ]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"Ordering the pathway LTα1β2→LTBR→NIK→RelB in cholangiocarcinoma established that noncanonical NF-κB is the dominant proliferative axis downstream of LTBR in epithelial cancer cells.\",\n      \"evidence\": \"LTα1β2 stimulation of CCA cell lines and patient-derived organoids with NIK inhibitor (B022), immunoblot, RNA-seq, and in vivo models\",\n      \"pmids\": [\"39164890\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"Contribution of canonical NF-κB to LTBR-driven proliferation not dissected in this system\",\n        \"Whether RelB target genes differ between cholangiocarcinoma and other LTBR-expressing cancers is unknown\"\n      ]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"Macrophage-specific LTBR knockout revealed that LTBR is required for maintaining immunosuppressive TAM identity, acting through both noncanonical NF-κB and Wnt/β-catenin — expanding LTBR function beyond lymphoid organogenesis to myeloid polarization.\",\n      \"evidence\": \"Conditional macrophage-specific LTBR knockout mice, flow cytometry, in vitro polarization, and tumor growth assays\",\n      \"pmids\": [\"39429877\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"The ligand activating LTBR on TAMs in the tumor microenvironment is not identified\",\n        \"Mechanism linking LTBR to Wnt/β-catenin activation in macrophages is not delineated\",\n        \"Independent replication in additional tumor models needed\"\n      ]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"A genome-wide CRISPR screen in patient-derived TIL–melanoma co-cultures uncovered that LTBR signaling on cancer cells is necessary for HLA class I-independent CD8+ T cell cytotoxicity, revealing a new effector mechanism requiring dual LTβR and IFN sensing.\",\n      \"evidence\": \"Whole-genome CRISPR loss-of-function screen, scRNA-seq/scTCR-seq of expanded TIL, functional validation (preprint)\",\n      \"pmids\": [\"bio_10.1101_2025.11.19.689204\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Preprint; awaits peer review and independent replication\",\n        \"Downstream death-signaling pathway triggered by LTβR on cancer cells (apoptosis vs. necroptosis) not resolved\",\n        \"Whether this mechanism extends beyond melanoma is untested\"\n      ]\n    },\n    {\n      \"year\": 2026,\n      \"claim\": \"Engineered stromal-targeted LTBR agonism demonstrated that LTBR activation is sufficient to reprogram tumor vasculature into high endothelial venules and induce tertiary lymphoid structures, directly linking receptor activation to immune infiltration.\",\n      \"evidence\": \"FAP-LTBR agonist fusion protein tested in primary human endothelial cells, 3D microfluidic models, multiple murine tumor models, spatial transcriptomics, and combination immunotherapy\",\n      \"pmids\": [\"42012453\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"Whether endogenous LTBR ligand levels in tumors are rate-limiting for HEV formation is unknown\",\n        \"Long-term stability of induced TLS after agonist withdrawal not assessed\"\n      ]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"Key unresolved questions include: which ligand(s) activate LTBR on macrophages in the tumor microenvironment, how LTBR signaling integrates with other TNF receptor superfamily members on the same cell, and whether the death-signaling versus survival-signaling switch controlled by TRAF5 stoichiometry operates across diverse tissue contexts.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"No structural model of the LTBR–TRAF5 complex exists\",\n        \"Relative contributions of LIGHT versus LTα1β2 in physiological tumor microenvironments are unmapped\",\n        \"Mechanism by which LTBR cross-talks with Wnt/β-catenin in macrophages is uncharacterized\"\n      ]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0060089\", \"supporting_discovery_ids\": [2, 4, 5]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005886\", \"supporting_discovery_ids\": [2, 4, 6]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"GO:0162482\", \"supporting_discovery_ids\": []},\n      {\"term_id\": \"R-HSA-162582\", \"supporting_discovery_ids\": [0, 2, 3, 4, 5]},\n      {\"term_id\": \"R-HSA-168256\", \"supporting_discovery_ids\": [0, 4, 5]},\n      {\"term_id\": \"R-HSA-5357801\", \"supporting_discovery_ids\": [1, 3]}\n    ],\n    \"complexes\": [],\n    \"partners\": [\n      \"TRAF5\",\n      \"TNFSF14\",\n      \"LTA\",\n      \"LTB\",\n      \"NIK\",\n      \"CREB1\"\n    ],\n    \"other_free_text\": []\n  }\n}\n```\n\n--- ROUND 2 (R2/R3, augmented corpus) ---\n\n```json\n{\n  \"mechanistic_narrative\": \"LTBR (lymphotoxin-beta receptor / TNFRSF3) is a TNF receptor superfamily member that transduces signals from the LTα1β2 heterotrimer and LIGHT (TNFSF14) to orchestrate lymphoid tissue organization, inflammatory gene expression, and cell death [PMID:8171323, PMID:9462508]. Upon ligand engagement, LTBR recruits TRAF3 to propagate apoptotic signaling and TRAF2/TRAF5 to activate two distinct NF-κB arms: a canonical IKKβ/NEMO-dependent pathway driving proinflammatory genes and a non-canonical NIK/IKKα-dependent pathway that processes p100 to p52/RelB and induces lymphoid organogenesis chemokines, with NIK/IKKα also phosphorylating p65 at Ser536 to enhance transcriptional activation [PMID:9122217, PMID:8663299, PMID:12387745, PMID:12419817]. In vivo, LTBR signaling is required for tertiary lymphoid structure formation and maintenance, drives hepatitis-associated hepatocellular carcinoma through hepatocyte IKKβ, sustains immunosuppressive M2 macrophage polarization via non-canonical NF-κB and Wnt/β-catenin, and—when activated by tumor-targeted LIGHT or FAP-directed agonists—remodels the tumor microenvironment to promote T cell infiltration and enhance immunotherapy efficacy [PMID:16934497, PMID:19800575, PMID:39429877, PMID:26977880, PMID:42012453]. Therapeutic blockade of LTBR in lung tissue disrupts inducible bronchus-associated lymphoid tissue and activates WNT/β-catenin-driven alveolar regeneration, reversing airway fibrosis in COPD models [PMID:33149305].\",\n  \"teleology\": [\n    {\n      \"year\": 1994,\n      \"claim\": \"Identifying the receptor for surface lymphotoxin established that LTα/LTβ heteromeric complexes signal through a dedicated receptor (LTBR) distinct from the TNF receptors that bind soluble LTα homotrimers, defining a new branch of TNF superfamily signaling.\",\n      \"evidence\": \"Receptor binding assays with purified LTα/LTβ heteromers\",\n      \"pmids\": [\"8171323\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Stoichiometry of the LTα/LTβ:LTBR complex not determined\", \"Intracellular signaling mechanism unknown at this point\"]\n    },\n    {\n      \"year\": 1997,\n      \"claim\": \"Mapping the adaptor recruitment profile of LTBR revealed that TRAF3 mediates LTBR-induced cell death while TRAF2 and TRAF5 contribute to NF-κB activation, establishing that LTBR bifurcates into independent death and transcriptional signaling arms through distinct TRAF proteins.\",\n      \"evidence\": \"Co-immunoprecipitation, dominant-negative TRAF3/TRAF5 mutants, NF-κB reporters, and cell death assays in multiple cell types\",\n      \"pmids\": [\"7859281\", \"8663299\", \"9122217\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Precise TRAF binding motifs on the LTBR cytoplasmic tail not resolved\", \"Whether other adaptors participate in either arm remained open\"]\n    },\n    {\n      \"year\": 1998,\n      \"claim\": \"Discovery that LIGHT (TNFSF14) is a second ligand for LTBR, independent of LTα/LTβ, expanded the receptor's functional repertoire and revealed regulation by decoy receptor DcR3, providing a framework for how LTBR signaling is tuned by ligand competition.\",\n      \"evidence\": \"Receptor-ligand binding assays, functional blocking, cytotoxicity assays with recombinant LIGHT and DcR3\",\n      \"pmids\": [\"9462508\", \"10318773\", \"10799510\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Relative physiological contribution of LIGHT versus LTα1β2 in different tissues unclear\", \"Structural basis of ligand selectivity not determined\"]\n    },\n    {\n      \"year\": 2002,\n      \"claim\": \"Demonstrating that LTBR activates two mechanistically distinct NF-κB pathways—canonical IKKβ/NEMO-dependent (proinflammatory genes) and non-canonical NIK/IKKα-dependent (p100→p52 processing, lymphoid chemokines)—with an additional NIK/IKKα-mediated p65-Ser536 phosphorylation step, resolved how a single receptor drives both acute inflammation and lymphoid organogenesis programs.\",\n      \"evidence\": \"Genetic epistasis in IKK-deficient MEFs, dominant-negative kinases, site-directed mutagenesis of p65-Ser536, chemokine expression profiling\",\n      \"pmids\": [\"12387745\", \"12419817\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Temporal kinetics of the two pathways in vivo not resolved\", \"Contribution of p65-Ser536 phosphorylation versus p52/RelB to specific gene targets uncharacterized\"]\n    },\n    {\n      \"year\": 2006,\n      \"claim\": \"Showing that LTBR signaling is necessary and sufficient for tertiary lymphoid organ (TLO) formation in vivo linked the non-canonical NF-κB chemokine program to organized ectopic lymphoid tissue development and autoimmune pathology.\",\n      \"evidence\": \"In vivo LIGHT blockade and islet-specific LIGHT transgenic mice in NOD diabetes model\",\n      \"pmids\": [\"16934497\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Cell-type-specific contributions of stromal versus immune LTBR in TLO maintenance not dissected\", \"Signals distinguishing protective versus pathogenic TLOs unknown\"]\n    },\n    {\n      \"year\": 2009,\n      \"claim\": \"Establishing that chronic hepatic LTα/LTβ–LTBR signaling drives HCC through hepatocyte IKKβ, independent of TNFR1, identified LTBR as a direct oncogenic driver in inflammation-associated liver cancer.\",\n      \"evidence\": \"Liver-specific LTαβ transgenic mice, IKKβ and TNFR1 genetic knockouts, in vivo LTβR blockade\",\n      \"pmids\": [\"19800575\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Downstream IKKβ target genes mediating hepatocyte transformation not fully catalogued\", \"Whether LTBR blockade can reverse established HCC not tested\"]\n    },\n    {\n      \"year\": 2016,\n      \"claim\": \"Tumor-targeted delivery of LIGHT demonstrated that activating LTBR signaling in the tumor stroma generates T cell-recruiting chemokines sufficient to overcome checkpoint blockade resistance, establishing LTBR agonism as a strategy for converting immune-cold tumors.\",\n      \"evidence\": \"Antibody-LIGHT fusion protein in syngeneic tumor models with combination anti-PD-L1 therapy\",\n      \"pmids\": [\"26977880\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Relative contribution of LTBR versus HVEM to LIGHT-mediated immune remodeling in tumors not separated\", \"Optimal LTBR engagement thresholds for efficacy versus toxicity unknown\"]\n    },\n    {\n      \"year\": 2020,\n      \"claim\": \"Demonstrating that LTBR blockade disrupts pathogenic iBALT, suppresses non-canonical NF-κB/TGFβ, and activates WNT/β-catenin-driven lung regeneration revealed LTBR as a therapeutic target in COPD and established a previously unrecognized connection between lymphotoxin signaling and epithelial progenitor cell fate.\",\n      \"evidence\": \"In vivo LTβR blocking in aged and cigarette-smoke-exposed mice, WNT reporter assays, validation in human COPD tissue\",\n      \"pmids\": [\"33149305\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Mechanism by which LTBR suppresses WNT signaling not molecularly defined\", \"Long-term safety of LTBR blockade for regenerative therapy not assessed\"]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"Cell-type-specific studies revealed that LTBR maintains immunosuppressive M2 macrophage polarization via non-canonical NF-κB/Wnt/β-catenin and that FAP-targeted LTBR agonism selectively activates endothelial cells to form TLS-like aggregates, refining the understanding of how LTBR controls different immune–stromal compartments in the tumor microenvironment.\",\n      \"evidence\": \"Macrophage-specific conditional LTBR knockout, TAM-targeted siRNA delivery, FAP-LTBR bispecific agonist in 3D microfluidic models and murine tumors, spatial transcriptomics\",\n      \"pmids\": [\"39429877\", \"42012453\", \"39164890\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"How LTBR agonism and antagonism in different cell types can be simultaneously exploited therapeutically is unresolved\", \"Whether macrophage LTBR signaling is relevant in non-tumor inflammatory settings not tested\", \"Findings from single labs await independent replication\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"Unresolved: the structural basis of LTBR signal complex assembly (TRAF stoichiometry, conformational activation), the precise molecular mechanism linking LTBR to WNT/β-catenin suppression, and the determinants separating protective (anti-tumor TLS) from pathogenic (autoimmune TLO, HCC-promoting) outcomes of LTBR signaling remain undefined.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"No crystal or cryo-EM structure of LTBR signaling complex\", \"Molecular intermediates between LTBR and WNT pathway not identified\", \"Context-dependent rules governing beneficial versus harmful LTBR activation not established\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0060089\", \"supporting_discovery_ids\": [0, 5, 7]},\n      {\"term_id\": \"GO:0060090\", \"supporting_discovery_ids\": [1, 2, 3]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005886\", \"supporting_discovery_ids\": [0, 1, 5, 7]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"GO:0005886\", \"supporting_discovery_ids\": [0]},\n      {\"term_id\": \"R-HSA-162582\", \"supporting_discovery_ids\": [2, 3, 8, 9, 14, 15, 17]},\n      {\"term_id\": \"R-HSA-168256\", \"supporting_discovery_ids\": [10, 12, 16, 19]},\n      {\"term_id\": \"R-HSA-5357801\", \"supporting_discovery_ids\": [3, 6, 7, 15]},\n      {\"term_id\": \"R-HSA-1643685\", \"supporting_discovery_ids\": [11, 17]}\n    ],\n    \"complexes\": [],\n    \"partners\": [\n      \"TRAF3\",\n      \"TRAF5\",\n      \"TRAF2\",\n      \"TRAF1\",\n      \"TNFSF14\",\n      \"LTA\",\n      \"LTB\",\n      \"TNFRSF6B\"\n    ],\n    \"other_free_text\": []\n  }\n}\n```"}