{"gene":"TFPI","run_date":"2026-06-13T19:06:35","timeline":{"discoveries":[{"year":1993,"finding":"TFPI inhibits factor VIIa-tissue factor complexes on cell surfaces through its first and second Kunitz-type domains (KD1 inhibits FVIIa, KD2 inhibits FXa); the third Kunitz-type domain and C-terminal tail are not essential for inhibition of cell surface FVIIa-tissue factor complexes, but influence cell-surface binding affinity. Factor Xa augments TFPI anticoagulant activity equally for full-length and truncated TFPI (TFPI1-161).","method":"In vitro kinetic assay comparing full-length recombinant TFPI vs. truncated TFPI1-161 on human bladder carcinoma J82 cell surfaces; chromogenic substrate assays; displacement studies","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 1 / Moderate — in vitro reconstitution with truncation constructs and kinetic assays, single lab but multiple orthogonal methods","pmids":["8473315"],"is_preprint":false},{"year":1992,"finding":"TFPI (as LACI) acts as a cofactor for heparin in inhibiting tissue factor-induced coagulation; TFPI and sulfated polysaccharides act synergistically in plasma to inhibit TF-induced clotting. TFPI does not significantly regulate the intrinsic (contact) pathway of coagulation.","method":"APTT and modified prothrombin time clotting assays using LACI-depleted plasma reconstituted with purified recombinant LACI and/or heparin; comparison of various sulfated polysaccharides","journal":"Blood","confidence":"High","confidence_rationale":"Tier 1 / Moderate — in vitro reconstitution assay with depleted and supplemented plasma, multiple polysaccharide comparisons, single lab","pmids":["1346095"],"is_preprint":false},{"year":1995,"finding":"Under normal physiologic conditions, TFPI expression is restricted to megakaryocytes and endothelium of the microvasculature; it is not synthesized by normal hepatocytes or large vessel endothelium. Under pathologic conditions, adherent monocytes/macrophages express both tissue factor and TFPI.","method":"Review synthesizing immunohistochemical and cell biology studies of TFPI expression sites","journal":"Thrombosis and haemostasis","confidence":"Medium","confidence_rationale":"Tier 3 / Strong — localization established by multiple prior experimental studies summarized in review, no new primary experiment reported","pmids":["7482419"],"is_preprint":false},{"year":1996,"finding":"Factor Xa-TFPI binary complex formation is required to inhibit factor VIIa-tissue factor; free factor Xa-TFPI (quaternary complex precursor) inversely correlates with factor VIIa and prothrombin fragment 1+2 levels in plasma, consistent with factor Xa-TFPI regulating both factor VIIa-tissue factor and prothrombinase in vivo.","method":"ELISA-based quantification of factor VIIa, prothrombin fragment 1+2, TFPI, and factor Xa-TFPI in plasma from 145 healthy adults; novel sandwich ELISA using affinity-purified rabbit anti-human TFPI IgG and chicken anti-human factor Xa-TFPI IgY","journal":"British journal of haematology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — novel ELISA quantification in large cohort with multiple correlative analyses, single lab, observational design","pmids":["8982054"],"is_preprint":false},{"year":2009,"finding":"Protein S acts as a cofactor for full-length TFPI, stimulating inhibition of factor Xa by TFPI approximately 10-fold. Free protein S and full-length TFPI form a complex in plasma, confirmed by protein S immunodepletion experiments and surface plasmon resonance. TFPI levels are reduced in hereditary and acquired protein S deficiency, and concomitant TFPI deficiency substantially contributes to the hypercoagulable state.","method":"Plasma TFPI and protein S antigen measurements; calibrated automated thrombography for thrombin generation; protein S immunodepletion; surface plasmon resonance to confirm protein S-TFPI interaction","journal":"Journal of thrombosis and haemostasis : JTH","confidence":"High","confidence_rationale":"Tier 1–2 / Strong — surface plasmon resonance plus functional thrombin generation assays plus immunodepletion, multiple orthogonal methods","pmids":["20002538"],"is_preprint":false},{"year":2009,"finding":"Protein S stimulates inhibition of factor Xa by full-length TFPI ~10-fold and is required for optimal TFPI anticoagulant activity; the TFPI/protein S system specifically inhibits TF pathway activation at low procoagulant stimuli. Protein S and TFPI constitute a constitutively active anticoagulant system in plasma, distinct from and cooperative with the APC pathway.","method":"Review summarizing functional plasma assays, thrombin generation experiments, and biochemical reconstitution studies from the authors' laboratory","journal":"Arteriosclerosis, thrombosis, and vascular biology","confidence":"High","confidence_rationale":"Tier 1 / Strong — findings based on independently replicated functional reconstitution and plasma assays described in detail","pmids":["19661488"],"is_preprint":false},{"year":2014,"finding":"TFPI inhibits MASP-2 of the lectin pathway of complement activation via its Kunitz-2 (KD2) domain, without affecting MASP-1, C1s, or C1r. This identifies TFPI as a novel selective inhibitor of MASP-2.","method":"Ex vivo lectin pathway activation assay (C4-deposition on mannan-coated plates); fluid-phase MASP-2 chromogenic activity assay; domain-mapping using recombinant TFPI and specific monoclonal antibodies against TFPI domains","journal":"European journal of immunology","confidence":"High","confidence_rationale":"Tier 1–2 / Moderate — in vitro enzymatic assay with domain-specific antibody mapping, multiple functional assays, single lab","pmids":["25359215"],"is_preprint":false},{"year":2015,"finding":"FXa inhibition by full-length TFPI is stimulated by negatively charged phospholipids (~5–6-fold), unfractionated heparin at low concentrations (~8-fold), physiological protein S (~2–3-fold), and FV (~2–3-fold). Thrombin-activated FVa impairs TFPI inhibition of FXa. These modulatory effects require the KD3-C-terminus region of TFPI, as TFPI1-150 is insensitive to these modulators. TFPI potently inhibits FXa-catalyzed prothrombin activation in absence of FVa but not in presence of FVa.","method":"Progress curve analysis of FXa inhibition using chromogenic substrate CS11-(65); comparison of full-length TFPI vs. TFPI1-150 constructs; systematic variation of phospholipids, heparin, prothrombin, FV, FVa, protein S","journal":"Thrombosis and haemostasis","confidence":"High","confidence_rationale":"Tier 1 / Moderate — rigorous in vitro kinetic assays with multiple modulators and truncation constructs, single lab","pmids":["26607136"],"is_preprint":false},{"year":2013,"finding":"TFPI directly inhibits FVIIa in a TF-dependent and phospholipid-dependent manner; the KD3-C-terminus significantly contributes to direct FVIIa inhibition (7–10-fold difference vs. constructs lacking KD3-C-terminus). KD2 also contributes to FVIIa inhibition. In the presence of FXa, a tight quaternary TF-FVIIa-TFPI-FXa complex forms requiring phospholipids and the Gla-domain of FXa but not KD3-C-terminus. Protein S stimulates TF-FVIIa inhibition by full-length TFPI (Ki reduced from 4.6 nM to 0.7 nM).","method":"Chromogenic substrate assays for FVIIa activity with relipidated or soluble TF; comparison of full-length TFPI, TFPI1-150, KD1-KD2, and KD1 constructs","journal":"Journal of thrombosis and haemostasis : JTH","confidence":"High","confidence_rationale":"Tier 1 / Moderate — in vitro reconstitution with multiple truncation constructs, rigorous kinetic analysis, single lab","pmids":["23347185"],"is_preprint":false},{"year":2014,"finding":"Full-length TFPI inhibits TF:FVIIa-catalyzed FIX activation (Ki=16.7 nM) and this is stimulated 16-fold by protein S (Ki=1.0 nM). All three Kunitz domains and the C-terminus are required for optimal inhibition of FIX activation, and single Kunitz domains are poor inhibitors (Ki >800 nM). Preformed FXa:TFPI complexes rapidly and stoichiometrically inhibit FIX and FX activation by TF:FVIIa, establishing binary TFPI:FXa complex formation as the rate-limiting step.","method":"Progress curve analysis of FXa and FIXa generation with chromogenic substrates; comparison of full-length TFPI, TFPI1-150, KD1-KD2, and single domain constructs; variation of phospholipid concentration","journal":"Journal of thrombosis and haemostasis : JTH","confidence":"High","confidence_rationale":"Tier 1 / Moderate — rigorous in vitro kinetic reconstitution with multiple constructs and conditions, single lab","pmids":["25163770"],"is_preprint":false},{"year":2022,"finding":"TFPI serves as a host cell receptor for TcdB from hypervirulent clade 2 Clostridioides difficile (TcdB2 and TcdB4). Cryo-EM structure of full-length TcdB4 with TFPI defined a common receptor-binding region in TcdB that is homologous to the Frizzled (FZD)-binding site in other TcdB variants. TFPI is highly expressed in intestinal glands (colonic crypts), and recombinant TFPI protects colonic epithelium from TcdB2/4.","method":"CRISPR/Cas9 genome-wide screen for TcdB4 receptor; cryo-EM structure determination of TcdB4-TFPI complex; recombinant TFPI protection assay of colonic epithelium","journal":"Cell","confidence":"High","confidence_rationale":"Tier 1 / Strong — cryo-EM structure combined with CRISPR screen and functional protection assay, rigorous multi-method study in high-impact journal","pmids":["35303428"],"is_preprint":false},{"year":2022,"finding":"TFPI is identified as a host receptor for TcdB4 (and TcdB10) from C. difficile. Intragenic micro-recombination events in the TcdB receptor-binding region determine whether TcdB variants bind TFPI or Frizzled proteins. Introduction of B4/B7-haplotype residues into TcdB1 enables dual recognition of TFPI and FZD. TcdB10 recognizes TFPI with species selectivity (chicken > mouse; not human, dog, or cattle).","method":"Genome-wide CRISPR-Cas9 screen; sequence analysis of 206 TcdB variants; mutagenesis introducing B4/B7-haplotype residues into TcdB1; cell-based binding and cytotoxicity assays","journal":"Nature communications","confidence":"High","confidence_rationale":"Tier 2 / Strong — CRISPR screen confirmed by mutagenesis and functional binding assays, replicated the TFPI receptor identification from Cell paper","pmids":["36351897"],"is_preprint":false},{"year":1992,"finding":"Rat TFPI cDNA encodes a 302-amino acid protein with three tandem Kunitz-type inhibitor domains conserved in length across human, rabbit, and rat TFPI. TFPI mRNA is expressed as two forms (4.0 and 1.4 kb) and is abundantly expressed in heart, lung, kidney, and aortic endothelial cells in rats.","method":"cDNA cloning from rat liver cDNA library; Northern blot analysis; amino acid sequence alignment and homology analysis","journal":"Journal of biochemistry","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — direct cDNA cloning and Northern blot characterization, single lab, structural characterization","pmids":["1639767"],"is_preprint":false},{"year":2009,"finding":"TFPI C-terminal peptides exhibit complement-dependent antibacterial activity against serum-resistant E. coli; C-terminal rTFPI fragments directly interact with the E. coli bacterial cell surface and kill bacteria through the complement pathway. Both complement-mediated killing and cell-surface binding are reversed by low amounts of heparin.","method":"Ex vivo blood culture killing assays with fragmented rTFPI and synthetic C-terminal TFPI peptides; serum complement-dependence assays; cell surface binding assays with reversal by heparin","journal":"The Journal of infectious diseases","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — multiple functional assays (killing, binding, heparin reversal) in ex vivo model, single lab","pmids":["19456231"],"is_preprint":false},{"year":2012,"finding":"Protein S acts as a cofactor for full-length TFPI, stimulating FXa inhibition by TFPI. The TFPI/protein S system fails to regulate FXa generation at high TF/FVIIa concentrations but can regain activity in the presence of APC, demonstrating an intertwinement of TFPI- and APC-cofactor activities of protein S.","method":"Review summarizing plasma thrombin generation assays, purified component reconstitution experiments, and functional studies from the authors' laboratory","journal":"Thrombosis research","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — functional plasma and reconstitution data reviewed, multi-method but review format","pmids":["22425215"],"is_preprint":false},{"year":2015,"finding":"TFPI1α (the anticoagulant protein TFPI) plays a role in driving the development of multiple drug resistance (MDR) in cancer but is not required for maintenance of the MDR state.","method":"Cancer cell line studies examining TFPI1α expression during doxorubicin resistance development (review with mechanistic discussion of primary experimental work)","journal":"Cancers","confidence":"Low","confidence_rationale":"Tier 3 / Weak — single lab review, mechanism not directly demonstrated in this paper, limited primary experimental detail in abstract","pmids":["26501324"],"is_preprint":false}],"current_model":"TFPI is a multivalent Kunitz-type serine protease inhibitor that downregulates the extrinsic coagulation pathway via a two-step mechanism: its KD2 domain first inhibits factor Xa, and the resulting binary FXa-TFPI complex then inhibits TF-FVIIa to form an inactive quaternary complex; KD1 inhibits FVIIa, KD3 and the C-terminal tail modulate FVIIa inhibition and cell-surface binding, and protein S acts as a cofactor that stimulates FXa inhibition ~10-fold by binding full-length TFPI; additionally, TFPI's KD2 inhibits MASP-2 of the lectin complement pathway, its C-terminal region has direct antibacterial activity through the complement system, and TFPI serves as a host cell receptor for clade 2 C. difficile TcdB variants in colonic crypts."},"narrative":{"mechanistic_narrative":"TFPI is a multivalent Kunitz-type serine protease inhibitor that constitutively downregulates the extrinsic (tissue factor) coagulation pathway [PMID:8473315, PMID:1346095]. It achieves this through a two-step, FXa-dependent mechanism in which its second Kunitz domain (KD2) inhibits factor Xa, and formation of the binary FXa-TFPI complex is the rate-limiting step required for subsequent inhibition of TF-FVIIa within a tight quaternary TF-FVIIa-TFPI-FXa complex; KD1 inhibits FVIIa while the KD3-C-terminus region confers cell-surface binding and modulates FVIIa inhibition [PMID:8473315, PMID:23347185, PMID:25163770]. Through this same machinery TFPI also inhibits TF:FVIIa-catalyzed activation of factors IX and X, with all three Kunitz domains and the C-terminus required for optimal activity [PMID:25163770]. TFPI activity is tuned by multiple cofactors acting on the KD3-C-terminus: protein S forms a plasma complex with full-length TFPI and stimulates FXa inhibition ~10-fold, and negatively charged phospholipids, heparin, and FV further enhance inhibition, while thrombin-activated FVa impairs it [PMID:20002538, PMID:26607136, PMID:23347185]. Heparin acts synergistically with TFPI to inhibit TF-induced clotting, and TFPI does not regulate the intrinsic contact pathway [PMID:1346095]. Beyond coagulation, TFPI selectively inhibits MASP-2 of the lectin complement pathway via KD2, and its C-terminal region exerts complement-dependent antibacterial activity that is reversible by heparin [PMID:25359215, PMID:19456231]. Independently of its protease-inhibitory role, TFPI serves as a host colonic-crypt receptor for hypervirulent clade 2 Clostridioides difficile TcdB variants (TcdB2/TcdB4), binding TcdB through a region homologous to the Frizzled-binding site [PMID:35303428, PMID:36351897].","teleology":[{"year":1992,"claim":"Establishing that TFPI (LACI) is a synergistic cofactor for heparin specific to the extrinsic pathway defined its position as a dedicated tissue-factor pathway regulator rather than a general anticoagulant.","evidence":"APTT/PT clotting assays with LACI-depleted plasma reconstituted with recombinant LACI and sulfated polysaccharides","pmids":["1346095"],"confidence":"High","gaps":["Did not resolve which domains mediate heparin synergy","Mechanism of polysaccharide enhancement not defined at molecular level"]},{"year":1992,"claim":"Cloning the cDNA across species defined TFPI as a three-tandem-Kunitz-domain protein and mapped broad tissue expression, providing the structural framework for later domain-function studies.","evidence":"Rat liver cDNA cloning, Northern blot, and cross-species sequence alignment","pmids":["1639767"],"confidence":"Medium","gaps":["Functional roles of individual domains not tested here","Two mRNA forms not functionally distinguished"]},{"year":1993,"claim":"Assigning KD1 to FVIIa inhibition and KD2 to FXa inhibition on cell surfaces resolved the division of labor between the Kunitz domains and showed KD3/C-terminus governs cell-surface binding rather than catalytic inhibition.","evidence":"In vitro kinetic assays comparing full-length vs. truncated TFPI1-161 on J82 carcinoma cell surfaces","pmids":["8473315"],"confidence":"High","gaps":["Quaternary complex assembly order not directly resolved","Physiological cell-surface anchoring partner not identified"]},{"year":1995,"claim":"Defining the restricted physiologic expression of TFPI to megakaryocytes and microvascular endothelium clarified where the inhibitor is produced and that hepatocytes are not the source.","evidence":"Review synthesizing immunohistochemical and cell-biology localization studies","pmids":["7482419"],"confidence":"Medium","gaps":["No new primary experiment","Quantitative contribution of each source to plasma pool unresolved"]},{"year":1996,"claim":"Showing that binary FXa-TFPI complex formation is required for TF-FVIIa inhibition and correlates inversely with coagulation markers in vivo extended the two-step mechanism from biochemistry into human plasma physiology.","evidence":"Novel sandwich ELISA quantification in 145 healthy adults","pmids":["8982054"],"confidence":"Medium","gaps":["Correlative/observational design","Causal direction not established in vivo"]},{"year":2009,"claim":"Identifying protein S as a plasma cofactor that stimulates FXa inhibition ~10-fold defined a constitutively active TFPI/protein S anticoagulant system and explained reduced TFPI in protein S deficiency.","evidence":"Plasma antigen measurements, calibrated thrombography, immunodepletion, and surface plasmon resonance","pmids":["20002538","19661488"],"confidence":"High","gaps":["Structural basis of protein S-TFPI binding not resolved","Relative in vivo weight versus APC pathway not quantified"]},{"year":2013,"claim":"Demonstrating direct, TF- and phospholipid-dependent FVIIa inhibition and mapping the KD3-C-terminus contribution refined how TFPI engages the initiating protease complex and quantified protein S enhancement of TF-FVIIa inhibition.","evidence":"Chromogenic FVIIa assays comparing full-length TFPI, TFPI1-150, KD1-KD2, and KD1 constructs","pmids":["23347185"],"confidence":"High","gaps":["Single-lab in vitro reconstitution","In vivo relevance of direct FVIIa inhibition vs. FXa-dependent route not weighted"]},{"year":2014,"claim":"Establishing binary TFPI:FXa formation as the rate-limiting step for inhibiting TF:FVIIa-catalyzed FIX and FX activation, with all domains required, unified the multi-domain architecture into a single kinetic model.","evidence":"Progress-curve kinetics of FXa/FIXa generation with full-length and truncation constructs","pmids":["25163770"],"confidence":"High","gaps":["Cellular validation of the kinetic model limited","Contribution of each cofactor to the rate-limiting step not separated"]},{"year":2014,"claim":"Identifying KD2-mediated selective inhibition of MASP-2 revealed a moonlighting role for TFPI as a regulator of the lectin complement pathway, distinct from its coagulation function.","evidence":"Lectin pathway C4-deposition assays and fluid-phase MASP-2 activity with domain-specific antibodies","pmids":["25359215"],"confidence":"High","gaps":["Physiological/in vivo significance of MASP-2 inhibition not established","Structural basis of KD2-MASP-2 selectivity unresolved"]},{"year":2015,"claim":"Systematic dissection of cofactors (phospholipids, heparin, protein S, FV, FVa) acting through the KD3-C-terminus defined how the TFPI:FXa reaction is environmentally tuned and is antagonized by activated FVa.","evidence":"Progress-curve FXa kinetics with full-length vs. TFPI1-150 across modulator conditions","pmids":["26607136"],"confidence":"High","gaps":["Integration of competing modulators in vivo not modeled","Structural mechanism of KD3-C-terminus sensitization unknown"]},{"year":2009,"claim":"Showing that TFPI C-terminal peptides kill serum-resistant E. coli via the complement pathway, reversibly by heparin, extended TFPI's C-terminus into innate antibacterial defense.","evidence":"Ex vivo blood-culture killing, bacterial surface-binding, and heparin-reversal assays with C-terminal rTFPI fragments","pmids":["19456231"],"confidence":"Medium","gaps":["In vivo antibacterial relevance not established","Molecular target on bacterial surface not identified"]},{"year":2022,"claim":"Identifying TFPI as the colonic-crypt host receptor for hypervirulent clade 2 C. difficile TcdB variants, and mapping the binding site, revealed a pathogen-exploited role for TFPI unrelated to protease inhibition.","evidence":"Genome-wide CRISPR screens, cryo-EM of TcdB4-TFPI, mutagenesis defining TFPI vs. Frizzled recognition, and recombinant TFPI epithelial protection assays","pmids":["35303428","36351897"],"confidence":"High","gaps":["Physiological consequence of TcdB-TFPI engagement for normal TFPI function unknown","Whether toxin binding alters anticoagulant activity untested"]},{"year":null,"claim":"How TFPI's distinct functions — coagulation inhibition, complement/MASP-2 regulation, antibacterial activity, and TcdB receptor role — are coordinated or regulated in a shared tissue context remains unresolved.","evidence":"","pmids":[],"confidence":"Low","gaps":["No structural model integrating multi-functional binding surfaces","Tissue-specific regulation of the different roles undefined","Causal disease links beyond correlative associations not established"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0140096","term_label":"catalytic activity, acting on a protein","supporting_discovery_ids":[0,8,9]},{"term_id":"GO:0098772","term_label":"molecular function regulator activity","supporting_discovery_ids":[0,1,4,6,7]},{"term_id":"GO:0001618","term_label":"virus receptor activity","supporting_discovery_ids":[10,11]},{"term_id":"GO:0008289","term_label":"lipid binding","supporting_discovery_ids":[7,8]}],"localization":[{"term_id":"GO:0005886","term_label":"plasma membrane","supporting_discovery_ids":[0,10]},{"term_id":"GO:0005576","term_label":"extracellular region","supporting_discovery_ids":[1,4]}],"pathway":[{"term_id":"R-HSA-109582","term_label":"Hemostasis","supporting_discovery_ids":[0,1,8,9]},{"term_id":"R-HSA-168256","term_label":"Immune System","supporting_discovery_ids":[6,13]},{"term_id":"R-HSA-1643685","term_label":"Disease","supporting_discovery_ids":[10,11]}],"complexes":["TF-FVIIa-TFPI-FXa quaternary complex","FXa-TFPI binary complex","protein S-TFPI complex"],"partners":["F7","F10","F9","PROS1","MASP2","F5","TCDB"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"P10646","full_name":"Tissue factor pathway inhibitor","aliases":["Extrinsic pathway inhibitor","EPI","Lipoprotein-associated coagulation inhibitor","LACI"],"length_aa":304,"mass_kda":35.0,"function":"Inhibits factor X (X(a)) directly and, in a Xa-dependent way, inhibits VIIa/tissue factor activity, presumably by forming a quaternary Xa/LACI/VIIa/TF complex. It possesses an antithrombotic action and also the ability to associate with lipoproteins in plasma","subcellular_location":"Microsome membrane","url":"https://www.uniprot.org/uniprotkb/P10646/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/TFPI","classification":"Not Classified","n_dependent_lines":2,"n_total_lines":1208,"dependency_fraction":0.0016556291390728477},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[],"url":"https://opencell.sf.czbiohub.org/search/TFPI","total_profiled":1310},"omim":[{"mim_id":"614489","title":"MICRO RNA 616; MIR616","url":"https://www.omim.org/entry/614489"},{"mim_id":"614348","title":"ANDROGEN-DEPENDENT TFPI-REGULATING PROTEIN; ADTRP","url":"https://www.omim.org/entry/614348"},{"mim_id":"613878","title":"COAGULATION FACTOR VII; F7","url":"https://www.omim.org/entry/613878"},{"mim_id":"600033","title":"TISSUE FACTOR PATHWAY INHIBITOR 2; TFPI2","url":"https://www.omim.org/entry/600033"},{"mim_id":"152310","title":"TISSUE FACTOR PATHWAY INHIBITOR; TFPI","url":"https://www.omim.org/entry/152310"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"","locations":[],"tissue_specificity":"Tissue enhanced","tissue_distribution":"Detected in all","driving_tissues":[{"tissue":"liver","ntpm":254.3},{"tissue":"placenta","ntpm":179.5}],"url":"https://www.proteinatlas.org/search/TFPI"},"hgnc":{"alias_symbol":["EPI","TFI","TFPI1"],"prev_symbol":["LACI"]},"alphafold":{"accession":"P10646","domains":[{"cath_id":"4.10.410.10","chopping":"47-119","consensus_level":"medium","plddt":85.7521,"start":47,"end":119},{"cath_id":"4.10.410.10","chopping":"122-179","consensus_level":"medium","plddt":91.6634,"start":122,"end":179},{"cath_id":"4.10.410.10","chopping":"216-269","consensus_level":"high","plddt":92.2165,"start":216,"end":269}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/P10646","model_url":"https://alphafold.ebi.ac.uk/files/AF-P10646-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-P10646-F1-predicted_aligned_error_v6.png","plddt_mean":73.62},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=TFPI","jax_strain_url":"https://www.jax.org/strain/search?query=TFPI"},"sequence":{"accession":"P10646","fasta_url":"https://rest.uniprot.org/uniprotkb/P10646.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/P10646/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/P10646"}},"corpus_meta":[{"pmid":"9271116","id":"PMC_9271116","title":"Null mutation of mCOUP-TFI results in defects in morphogenesis of the glossopharyngeal ganglion, axonal projection, and arborization.","date":"1997","source":"Genes & development","url":"https://pubmed.ncbi.nlm.nih.gov/9271116","citation_count":195,"is_preprint":false},{"pmid":"19160499","id":"PMC_19160499","title":"Requirement for COUP-TFI and II in the temporal specification of neural stem cells in CNS development.","date":"2008","source":"Nature neuroscience","url":"https://pubmed.ncbi.nlm.nih.gov/19160499","citation_count":189,"is_preprint":false},{"pmid":"17828260","id":"PMC_17828260","title":"COUP-TFI regulates the balance of cortical patterning between frontal/motor and sensory areas.","date":"2007","source":"Nature neuroscience","url":"https://pubmed.ncbi.nlm.nih.gov/17828260","citation_count":188,"is_preprint":false},{"pmid":"1660424","id":"PMC_1660424","title":"Spontaneous mutation in the Escherichia coli lacI gene.","date":"1991","source":"Genetics","url":"https://pubmed.ncbi.nlm.nih.gov/1660424","citation_count":187,"is_preprint":false},{"pmid":"19269243","id":"PMC_19269243","title":"Allostery in the LacI/GalR family: variations on a theme.","date":"2009","source":"Current opinion in microbiology","url":"https://pubmed.ncbi.nlm.nih.gov/19269243","citation_count":133,"is_preprint":false},{"pmid":"10899129","id":"PMC_10899129","title":"SsrA-mediated tagging and proteolysis of LacI and its role in the regulation of lac operon.","date":"2000","source":"The EMBO journal","url":"https://pubmed.ncbi.nlm.nih.gov/10899129","citation_count":118,"is_preprint":false},{"pmid":"18165280","id":"PMC_18165280","title":"COUP-TFI coordinates cortical patterning, neurogenesis, and laminar fate and modulates MAPK/ERK, AKT, and beta-catenin signaling.","date":"2007","source":"Cerebral cortex (New York, N.Y. : 1991)","url":"https://pubmed.ncbi.nlm.nih.gov/18165280","citation_count":118,"is_preprint":false},{"pmid":"26638884","id":"PMC_26638884","title":"Epi-Drugs and Epi-miRs: Moving Beyond Current Cancer Therapies.","date":"2016","source":"Current cancer drug targets","url":"https://pubmed.ncbi.nlm.nih.gov/26638884","citation_count":116,"is_preprint":false},{"pmid":"10620335","id":"PMC_10620335","title":"The aryl hydrocarbon receptor interacts with estrogen receptor alpha and orphan receptors COUP-TFI and ERRalpha1.","date":"2000","source":"Archives of biochemistry and biophysics","url":"https://pubmed.ncbi.nlm.nih.gov/10620335","citation_count":102,"is_preprint":false},{"pmid":"7482419","id":"PMC_7482419","title":"Sites of tissue factor pathway inhibitor (TFPI) and tissue factor expression under physiologic and pathologic conditions. On behalf of the Subcommittee on Tissue factor Pathway Inhibitor (TFPI) of the Scientific and Standardization Committee of the ISTH.","date":"1995","source":"Thrombosis and haemostasis","url":"https://pubmed.ncbi.nlm.nih.gov/7482419","citation_count":102,"is_preprint":false},{"pmid":"11027229","id":"PMC_11027229","title":"Differential expression of COUP-TFI, CHL1, and two novel genes in developing neocortex identified by differential display PCR.","date":"2000","source":"The Journal of neuroscience : the official journal of the Society for Neuroscience","url":"https://pubmed.ncbi.nlm.nih.gov/11027229","citation_count":101,"is_preprint":false},{"pmid":"32205444","id":"PMC_32205444","title":"15-Epi-LXA4 and 17-epi-RvD1 restore TLR9-mediated impaired neutrophil phagocytosis and accelerate resolution of lung inflammation.","date":"2020","source":"Proceedings of the National Academy of Sciences of the United States of America","url":"https://pubmed.ncbi.nlm.nih.gov/32205444","citation_count":91,"is_preprint":false},{"pmid":"31218726","id":"PMC_31218726","title":"Epigenetic polypharmacology: A new frontier for epi-drug discovery.","date":"2019","source":"Medicinal research reviews","url":"https://pubmed.ncbi.nlm.nih.gov/31218726","citation_count":88,"is_preprint":false},{"pmid":"8979119","id":"PMC_8979119","title":"Tissue factor pathway inhibitor (TFPI)--an update.","date":"1996","source":"Haemostasis","url":"https://pubmed.ncbi.nlm.nih.gov/8979119","citation_count":85,"is_preprint":false},{"pmid":"17021036","id":"PMC_17021036","title":"COUP-TFI is required for the formation of commissural projections in the forebrain by regulating axonal growth.","date":"2006","source":"Development (Cambridge, England)","url":"https://pubmed.ncbi.nlm.nih.gov/17021036","citation_count":81,"is_preprint":false},{"pmid":"33938389","id":"PMC_33938389","title":"Completion of the gut microbial epi-bile acid pathway.","date":"2021","source":"Gut microbes","url":"https://pubmed.ncbi.nlm.nih.gov/33938389","citation_count":79,"is_preprint":false},{"pmid":"24467947","id":"PMC_24467947","title":"Design and analysis of LacI-repressed promoters and DNA-looping in a cyanobacterium.","date":"2014","source":"Journal of biological engineering","url":"https://pubmed.ncbi.nlm.nih.gov/24467947","citation_count":71,"is_preprint":false},{"pmid":"8473315","id":"PMC_8473315","title":"Inhibitory properties of full-length and truncated recombinant tissue factor pathway inhibitor (TFPI). Evidence that the third Kunitz-type domain of TFPI is not essential for the inhibition of factor VIIa-tissue factor complexes on cell surfaces.","date":"1993","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/8473315","citation_count":71,"is_preprint":false},{"pmid":"24966856","id":"PMC_24966856","title":"Comparative genomics and evolution of regulons of the LacI-family transcription factors.","date":"2014","source":"Frontiers in microbiology","url":"https://pubmed.ncbi.nlm.nih.gov/24966856","citation_count":68,"is_preprint":false},{"pmid":"20002538","id":"PMC_20002538","title":"Hereditary and acquired protein S deficiencies are associated with low TFPI levels in plasma.","date":"2009","source":"Journal of thrombosis and haemostasis : JTH","url":"https://pubmed.ncbi.nlm.nih.gov/20002538","citation_count":66,"is_preprint":false},{"pmid":"35303428","id":"PMC_35303428","title":"TFPI is a colonic crypt receptor for TcdB from hypervirulent clade 2 C. difficile.","date":"2022","source":"Cell","url":"https://pubmed.ncbi.nlm.nih.gov/35303428","citation_count":61,"is_preprint":false},{"pmid":"16056260","id":"PMC_16056260","title":"Tissue, cell and stage specificity of (epi)mutations in cancers.","date":"2005","source":"Nature reviews. Cancer","url":"https://pubmed.ncbi.nlm.nih.gov/16056260","citation_count":61,"is_preprint":false},{"pmid":"30878492","id":"PMC_30878492","title":"Primers on nutrigenetics and nutri(epi)genomics: Origins and development of precision nutrition.","date":"2019","source":"Biochimie","url":"https://pubmed.ncbi.nlm.nih.gov/30878492","citation_count":57,"is_preprint":false},{"pmid":"36979957","id":"PMC_36979957","title":"Endometriosis: Update of Pathophysiology, (Epi) Genetic and Environmental Involvement.","date":"2023","source":"Biomedicines","url":"https://pubmed.ncbi.nlm.nih.gov/36979957","citation_count":56,"is_preprint":false},{"pmid":"21965613","id":"PMC_21965613","title":"COUP-TFI promotes radial migration and proper morphology of callosal projection neurons by repressing Rnd2 expression.","date":"2011","source":"Development (Cambridge, England)","url":"https://pubmed.ncbi.nlm.nih.gov/21965613","citation_count":56,"is_preprint":false},{"pmid":"19630792","id":"PMC_19630792","title":"Regulation of TFPI function by protein S.","date":"2009","source":"Journal of thrombosis and haemostasis : JTH","url":"https://pubmed.ncbi.nlm.nih.gov/19630792","citation_count":55,"is_preprint":false},{"pmid":"1346095","id":"PMC_1346095","title":"Lipoprotein-associated coagulation inhibitor (LACI) is a cofactor for heparin: synergistic anticoagulant action between LACI and sulfated polysaccharides.","date":"1992","source":"Blood","url":"https://pubmed.ncbi.nlm.nih.gov/1346095","citation_count":55,"is_preprint":false},{"pmid":"14738874","id":"PMC_14738874","title":"The nuclear orphan receptor COUP-TFI is important for differentiation of oligodendrocytes.","date":"2004","source":"Developmental biology","url":"https://pubmed.ncbi.nlm.nih.gov/14738874","citation_count":54,"is_preprint":false},{"pmid":"9684799","id":"PMC_9684799","title":"Correlates of antithrombin, protein C, protein S, and TFPI in a healthy elderly cohort.","date":"1998","source":"Thrombosis and haemostasis","url":"https://pubmed.ncbi.nlm.nih.gov/9684799","citation_count":53,"is_preprint":false},{"pmid":"29709504","id":"PMC_29709504","title":"The pleiotropic transcriptional regulator COUP-TFI plays multiple roles in neural development and disease.","date":"2018","source":"Brain research","url":"https://pubmed.ncbi.nlm.nih.gov/29709504","citation_count":49,"is_preprint":false},{"pmid":"19661488","id":"PMC_19661488","title":"Protein S as cofactor for TFPI.","date":"2009","source":"Arteriosclerosis, thrombosis, and vascular biology","url":"https://pubmed.ncbi.nlm.nih.gov/19661488","citation_count":49,"is_preprint":false},{"pmid":"30302740","id":"PMC_30302740","title":"Anti-tissue factor pathway inhibitor (TFPI) therapy: a novel approach to the treatment of haemophilia.","date":"2018","source":"International journal of hematology","url":"https://pubmed.ncbi.nlm.nih.gov/30302740","citation_count":49,"is_preprint":false},{"pmid":"19210754","id":"PMC_19210754","title":"Genetics, epigenetics and pharmaco-(epi)genomics in angiogenesis.","date":"2008","source":"Journal of cellular and molecular medicine","url":"https://pubmed.ncbi.nlm.nih.gov/19210754","citation_count":47,"is_preprint":false},{"pmid":"19212621","id":"PMC_19212621","title":"EGCG inhibits growth and induces apoptosis in renal cell carcinoma through TFPI-2 overexpression.","date":"2009","source":"Oncology reports","url":"https://pubmed.ncbi.nlm.nih.gov/19212621","citation_count":46,"is_preprint":false},{"pmid":"23479317","id":"PMC_23479317","title":"Pericardioscopy and epi- and pericardial biopsy - a new window to the heart improving etiological diagnoses and permitting targeted intrapericardial therapy.","date":"2013","source":"Heart failure reviews","url":"https://pubmed.ncbi.nlm.nih.gov/23479317","citation_count":44,"is_preprint":false},{"pmid":"29845491","id":"PMC_29845491","title":"Inhibition of Tissue Factor Pathway Inhibitor (TFPI) as a Treatment for Haemophilia: Rationale with Focus on Concizumab.","date":"2018","source":"Drugs","url":"https://pubmed.ncbi.nlm.nih.gov/29845491","citation_count":43,"is_preprint":false},{"pmid":"20553382","id":"PMC_20553382","title":"Atorvastatin or transgenic expression of TFPI inhibits coagulation initiated by anti-nonGal IgG binding to porcine aortic endothelial cells.","date":"2010","source":"Journal of thrombosis and haemostasis : JTH","url":"https://pubmed.ncbi.nlm.nih.gov/20553382","citation_count":43,"is_preprint":false},{"pmid":"21062455","id":"PMC_21062455","title":"TFPI-2 is a putative tumor suppressor gene frequently inactivated by promoter hypermethylation in nasopharyngeal carcinoma.","date":"2010","source":"BMC cancer","url":"https://pubmed.ncbi.nlm.nih.gov/21062455","citation_count":43,"is_preprint":false},{"pmid":"20062932","id":"PMC_20062932","title":"Expression of tissue factor pathway inhibitor (TFPI) in human breast and colon cancer tissue.","date":"2009","source":"Thrombosis and haemostasis","url":"https://pubmed.ncbi.nlm.nih.gov/20062932","citation_count":42,"is_preprint":false},{"pmid":"16914494","id":"PMC_16914494","title":"COUP-TFI controls Notch regulation of hair cell and support cell differentiation.","date":"2006","source":"Development (Cambridge, England)","url":"https://pubmed.ncbi.nlm.nih.gov/16914494","citation_count":41,"is_preprint":false},{"pmid":"22449186","id":"PMC_22449186","title":"Methylation of TFPI-2 is an early event of esophageal carcinogenesis.","date":"2012","source":"Epigenomics","url":"https://pubmed.ncbi.nlm.nih.gov/22449186","citation_count":41,"is_preprint":false},{"pmid":"12093745","id":"PMC_12093745","title":"Formation of an hER alpha-COUP-TFI complex enhances hER alpha AF-1 through Ser118 phosphorylation by MAPK.","date":"2002","source":"The EMBO journal","url":"https://pubmed.ncbi.nlm.nih.gov/12093745","citation_count":38,"is_preprint":false},{"pmid":"12972613","id":"PMC_12972613","title":"Repression of the luteinizing hormone receptor gene promoter by cross talk among EAR3/COUP-TFI, Sp1/Sp3, and TFIIB.","date":"2003","source":"Molecular and cellular biology","url":"https://pubmed.ncbi.nlm.nih.gov/12972613","citation_count":37,"is_preprint":false},{"pmid":"35642676","id":"PMC_35642676","title":"Epi-immunotherapy for cancers: rationales of epi-drugs in combination with immunotherapy and advances in clinical trials.","date":"2022","source":"Cancer communications (London, England)","url":"https://pubmed.ncbi.nlm.nih.gov/35642676","citation_count":36,"is_preprint":false},{"pmid":"20111703","id":"PMC_20111703","title":"Genome-wide analysis of binding sites and direct target genes of the orphan nuclear receptor NR2F1/COUP-TFI.","date":"2010","source":"PloS one","url":"https://pubmed.ncbi.nlm.nih.gov/20111703","citation_count":36,"is_preprint":false},{"pmid":"31252410","id":"PMC_31252410","title":"The evolving (epi)genetic landscape of pancreatic neuroendocrine tumours.","date":"2019","source":"Endocrine-related cancer","url":"https://pubmed.ncbi.nlm.nih.gov/31252410","citation_count":36,"is_preprint":false},{"pmid":"30170355","id":"PMC_30170355","title":"Epigenetics and Epi-miRNAs: Potential markers/therapeutics in leukemia.","date":"2018","source":"Biomedicine & pharmacotherapy = Biomedecine & pharmacotherapie","url":"https://pubmed.ncbi.nlm.nih.gov/30170355","citation_count":35,"is_preprint":false},{"pmid":"34901902","id":"PMC_34901902","title":"Applications and potentials of nanopore sequencing in the (epi)genome and (epi)transcriptome era.","date":"2021","source":"Innovation (Cambridge (Mass.))","url":"https://pubmed.ncbi.nlm.nih.gov/34901902","citation_count":34,"is_preprint":false},{"pmid":"9560364","id":"PMC_9560364","title":"The lacI gene as a target for mutation in transgenic rodents and Escherichia coli.","date":"1998","source":"Genetics","url":"https://pubmed.ncbi.nlm.nih.gov/9560364","citation_count":34,"is_preprint":false},{"pmid":"26607136","id":"PMC_26607136","title":"Role of exosite binding modulators in the inhibition of Fxa by TFPI.","date":"2015","source":"Thrombosis and haemostasis","url":"https://pubmed.ncbi.nlm.nih.gov/26607136","citation_count":34,"is_preprint":false},{"pmid":"26813976","id":"PMC_26813976","title":"Gradient COUP-TFI Expression Is Required for Functional Organization of the Hippocampal Septo-Temporal Longitudinal Axis.","date":"2017","source":"Cerebral cortex (New York, N.Y. : 1991)","url":"https://pubmed.ncbi.nlm.nih.gov/26813976","citation_count":34,"is_preprint":false},{"pmid":"25359215","id":"PMC_25359215","title":"TFPI inhibits lectin pathway of complement activation by direct interaction with MASP-2.","date":"2014","source":"European journal of immunology","url":"https://pubmed.ncbi.nlm.nih.gov/25359215","citation_count":33,"is_preprint":false},{"pmid":"1639767","id":"PMC_1639767","title":"cDNA cloning and expression of rat tissue factor pathway inhibitor (TFPI).","date":"1992","source":"Journal of biochemistry","url":"https://pubmed.ncbi.nlm.nih.gov/1639767","citation_count":33,"is_preprint":false},{"pmid":"21530612","id":"PMC_21530612","title":"Knockdown of TFPI-2 promotes migration and invasion of glioma cells.","date":"2011","source":"Neuroscience letters","url":"https://pubmed.ncbi.nlm.nih.gov/21530612","citation_count":33,"is_preprint":false},{"pmid":"35911511","id":"PMC_35911511","title":"Epi-Drugs in Heart Failure.","date":"2022","source":"Frontiers in cardiovascular medicine","url":"https://pubmed.ncbi.nlm.nih.gov/35911511","citation_count":32,"is_preprint":false},{"pmid":"27207418","id":"PMC_27207418","title":"Targeting TFPI for hemophilia treatment.","date":"2016","source":"Thrombosis research","url":"https://pubmed.ncbi.nlm.nih.gov/27207418","citation_count":32,"is_preprint":false},{"pmid":"22197177","id":"PMC_22197177","title":"Tissue factor/TFPI and blood cells.","date":"2011","source":"Thrombosis research","url":"https://pubmed.ncbi.nlm.nih.gov/22197177","citation_count":32,"is_preprint":false},{"pmid":"24906407","id":"PMC_24906407","title":"COUP-TFI modifies CXCL12 and CXCR4 expression by activating EGF signaling and stimulates breast cancer cell migration.","date":"2014","source":"BMC cancer","url":"https://pubmed.ncbi.nlm.nih.gov/24906407","citation_count":32,"is_preprint":false},{"pmid":"17674191","id":"PMC_17674191","title":"COUP-TFI modulates estrogen signaling and influences proliferation, survival and migration of breast cancer cells.","date":"2007","source":"Breast cancer research and treatment","url":"https://pubmed.ncbi.nlm.nih.gov/17674191","citation_count":30,"is_preprint":false},{"pmid":"26501324","id":"PMC_26501324","title":"Development, Maintenance, and Reversal of Multiple Drug Resistance: At the Crossroads of TFPI1, ABC Transporters, and HIF1.","date":"2015","source":"Cancers","url":"https://pubmed.ncbi.nlm.nih.gov/26501324","citation_count":29,"is_preprint":false},{"pmid":"24227652","id":"PMC_24227652","title":"COUP-TFI controls activity-dependent tyrosine hydroxylase expression in adult dopaminergic olfactory bulb interneurons.","date":"2013","source":"Development (Cambridge, England)","url":"https://pubmed.ncbi.nlm.nih.gov/24227652","citation_count":28,"is_preprint":false},{"pmid":"12956419","id":"PMC_12956419","title":"Transcriptional silencing of the TFPI-2 gene by promoter hypermethylation in choriocarcinoma cells.","date":"2003","source":"Biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/12956419","citation_count":28,"is_preprint":false},{"pmid":"11682620","id":"PMC_11682620","title":"EAR2 and EAR3/COUP-TFI regulate transcription of the rat LH receptor.","date":"2001","source":"Molecular endocrinology (Baltimore, Md.)","url":"https://pubmed.ncbi.nlm.nih.gov/11682620","citation_count":27,"is_preprint":false},{"pmid":"19016004","id":"PMC_19016004","title":"Blood coagulation and fibrinolysis in patients with acromegaly: increased plasminogen activator inhibitor-1 (PAI-1), decreased tissue factor pathway inhibitor (TFPI), and an inverse correlation between growth hormone and TFPI.","date":"2008","source":"Endocrine","url":"https://pubmed.ncbi.nlm.nih.gov/19016004","citation_count":27,"is_preprint":false},{"pmid":"26205296","id":"PMC_26205296","title":"RNA (Epi)genetics in cardiovascular diseases.","date":"2015","source":"Journal of molecular and cellular cardiology","url":"https://pubmed.ncbi.nlm.nih.gov/26205296","citation_count":26,"is_preprint":false},{"pmid":"25163770","id":"PMC_25163770","title":"Inhibition of tissue factor:factor VIIa-catalyzed factor IX and factor X activation by TFPI and TFPI constructs.","date":"2014","source":"Journal of thrombosis and haemostasis : JTH","url":"https://pubmed.ncbi.nlm.nih.gov/25163770","citation_count":26,"is_preprint":false},{"pmid":"11168401","id":"PMC_11168401","title":"COUP-TFI and COUP-TFII regulate expression of the NHE through a nuclear hormone responsive element with enhancer activity.","date":"2001","source":"European journal of biochemistry","url":"https://pubmed.ncbi.nlm.nih.gov/11168401","citation_count":26,"is_preprint":false},{"pmid":"33570646","id":"PMC_33570646","title":"Concizumab: a novel anti-TFPI therapeutic for hemophilia.","date":"2021","source":"Blood advances","url":"https://pubmed.ncbi.nlm.nih.gov/33570646","citation_count":26,"is_preprint":false},{"pmid":"32620673","id":"PMC_32620673","title":"Remodeling the epigenome and (epi)cytoskeleton: a new paradigm for co-regulation by methylation.","date":"2020","source":"The Journal of experimental biology","url":"https://pubmed.ncbi.nlm.nih.gov/32620673","citation_count":25,"is_preprint":false},{"pmid":"26097484","id":"PMC_26097484","title":"Epi-fingerprinting and epi-interventions for improved crop production and food quality.","date":"2015","source":"Frontiers in plant science","url":"https://pubmed.ncbi.nlm.nih.gov/26097484","citation_count":24,"is_preprint":false},{"pmid":"8982054","id":"PMC_8982054","title":"Probable regulation of factor VIIa-tissue factor and prothrombinase by factor Xa-TFPI and TFPI in vivo.","date":"1996","source":"British journal of haematology","url":"https://pubmed.ncbi.nlm.nih.gov/8982054","citation_count":24,"is_preprint":false},{"pmid":"25922524","id":"PMC_25922524","title":"Transcription factors COUP-TFI and COUP-TFII are required for the production of granule cells in the mouse olfactory bulb.","date":"2015","source":"Development (Cambridge, England)","url":"https://pubmed.ncbi.nlm.nih.gov/25922524","citation_count":24,"is_preprint":false},{"pmid":"17579209","id":"PMC_17579209","title":"Deoxyribonucleic acid methyl transferases 3a and 3b associate with the nuclear orphan receptor COUP-TFI during gene activation.","date":"2007","source":"Molecular endocrinology (Baltimore, Md.)","url":"https://pubmed.ncbi.nlm.nih.gov/17579209","citation_count":24,"is_preprint":false},{"pmid":"22425215","id":"PMC_22425215","title":"TFPI-dependent activities of protein S.","date":"2012","source":"Thrombosis research","url":"https://pubmed.ncbi.nlm.nih.gov/22425215","citation_count":23,"is_preprint":false},{"pmid":"24058367","id":"PMC_24058367","title":"(Epi)genetics of pregnancy-associated diseases.","date":"2013","source":"Frontiers in genetics","url":"https://pubmed.ncbi.nlm.nih.gov/24058367","citation_count":23,"is_preprint":false},{"pmid":"36351897","id":"PMC_36351897","title":"Identification of TFPI as a receptor reveals recombination-driven receptor switching in Clostridioides difficile toxin B variants.","date":"2022","source":"Nature communications","url":"https://pubmed.ncbi.nlm.nih.gov/36351897","citation_count":23,"is_preprint":false},{"pmid":"9851803","id":"PMC_9851803","title":"COUP-TFI expression in human adrenocortical adenomas: possible role in steroidogenesis.","date":"1998","source":"The Journal of clinical endocrinology and metabolism","url":"https://pubmed.ncbi.nlm.nih.gov/9851803","citation_count":23,"is_preprint":false},{"pmid":"9862192","id":"PMC_9862192","title":"Mutation studies in lacI transgenic mice after exposure to radiation or cyclophosphamide.","date":"1998","source":"Mutagenesis","url":"https://pubmed.ncbi.nlm.nih.gov/9862192","citation_count":23,"is_preprint":false},{"pmid":"28506990","id":"PMC_28506990","title":"COUP-TFI mitotically regulates production and migration of dentate granule cells and modulates hippocampal Cxcr4 expression.","date":"2017","source":"Development (Cambridge, England)","url":"https://pubmed.ncbi.nlm.nih.gov/28506990","citation_count":22,"is_preprint":false},{"pmid":"17180732","id":"PMC_17180732","title":"Protein and mRNA expression of tissue factor pathway inhibitor-1 (TFPI-1) in breast, pancreatic and colorectal cancer cells.","date":"2006","source":"Molecular biology reports","url":"https://pubmed.ncbi.nlm.nih.gov/17180732","citation_count":22,"is_preprint":false},{"pmid":"23347185","id":"PMC_23347185","title":"Direct inhibition of factor VIIa by TFPI and TFPI constructs.","date":"2013","source":"Journal of thrombosis and haemostasis : JTH","url":"https://pubmed.ncbi.nlm.nih.gov/23347185","citation_count":21,"is_preprint":false},{"pmid":"22405586","id":"PMC_22405586","title":"Hemostatic properties of a TFPI antibody.","date":"2012","source":"Thrombosis research","url":"https://pubmed.ncbi.nlm.nih.gov/22405586","citation_count":21,"is_preprint":false},{"pmid":"15907456","id":"PMC_15907456","title":"Dynamic expression of COUP-TFI and COUP-TFII during development and functional maturation of the mouse inner ear.","date":"2005","source":"Gene expression patterns : GEP","url":"https://pubmed.ncbi.nlm.nih.gov/15907456","citation_count":21,"is_preprint":false},{"pmid":"25120267","id":"PMC_25120267","title":"Multiple LacI-mediated loops revealed by Bayesian statistics and tethered particle motion.","date":"2014","source":"Nucleic acids research","url":"https://pubmed.ncbi.nlm.nih.gov/25120267","citation_count":21,"is_preprint":false},{"pmid":"8945635","id":"PMC_8945635","title":"Cloning of the cDNA encoding mouse PP5/TFPI-2 and mapping of the gene to chromosome 6.","date":"1996","source":"DNA and cell biology","url":"https://pubmed.ncbi.nlm.nih.gov/8945635","citation_count":21,"is_preprint":false},{"pmid":"11434780","id":"PMC_11434780","title":"Ion concentration and temperature dependence of DNA binding: comparison of PurR and LacI repressor proteins.","date":"2001","source":"Biochemistry","url":"https://pubmed.ncbi.nlm.nih.gov/11434780","citation_count":20,"is_preprint":false},{"pmid":"28039717","id":"PMC_28039717","title":"TFPI-2 expression is decreased in bladder cancer and is related to apoptosis.","date":"2016","source":"Journal of B.U.ON. : official journal of the Balkan Union of Oncology","url":"https://pubmed.ncbi.nlm.nih.gov/28039717","citation_count":19,"is_preprint":false},{"pmid":"7686256","id":"PMC_7686256","title":"Large-scale mutational analysis of EMS-induced mutation in the lacI gene of Escherichia coli.","date":"1993","source":"Mutation research","url":"https://pubmed.ncbi.nlm.nih.gov/7686256","citation_count":19,"is_preprint":false},{"pmid":"32903053","id":"PMC_32903053","title":"Diffusion-Weighted MRI to Assess Sacroiliitis: Improved Image Quality and Diagnostic Performance of Readout-Segmented Echo-Planar Imaging (EPI) Over Conventional Single-Shot EPI.","date":"2021","source":"AJR. American journal of roentgenology","url":"https://pubmed.ncbi.nlm.nih.gov/32903053","citation_count":19,"is_preprint":false},{"pmid":"17543441","id":"PMC_17543441","title":"Integration host factor alters LacI-induced DNA looping.","date":"2007","source":"Biophysical chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/17543441","citation_count":18,"is_preprint":false},{"pmid":"26342073","id":"PMC_26342073","title":"Flexibility and Disorder in Gene Regulation: LacI/GalR and Hox Proteins.","date":"2015","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/26342073","citation_count":17,"is_preprint":false},{"pmid":"35580998","id":"PMC_35580998","title":"Epi-miRNAs: Modern mediators of methylation status in human cancers.","date":"2022","source":"Wiley interdisciplinary reviews. RNA","url":"https://pubmed.ncbi.nlm.nih.gov/35580998","citation_count":17,"is_preprint":false},{"pmid":"31396617","id":"PMC_31396617","title":"Enhancement of LacI binding in vivo.","date":"2019","source":"Nucleic acids research","url":"https://pubmed.ncbi.nlm.nih.gov/31396617","citation_count":17,"is_preprint":false},{"pmid":"25568449","id":"PMC_25568449","title":"Adding 'epi-' to behaviour genetics: implications for animal domestication.","date":"2015","source":"The Journal of experimental biology","url":"https://pubmed.ncbi.nlm.nih.gov/25568449","citation_count":17,"is_preprint":false},{"pmid":"11209985","id":"PMC_11209985","title":"Future possibilities in the regulation of the extrinsic pathway: rFVIIa and TFPI.","date":"2000","source":"Annals of medicine","url":"https://pubmed.ncbi.nlm.nih.gov/11209985","citation_count":17,"is_preprint":false},{"pmid":"16646090","id":"PMC_16646090","title":"LacO-LacI interaction in affinity adsorption of plasmid DNA.","date":"2006","source":"Biotechnology and bioengineering","url":"https://pubmed.ncbi.nlm.nih.gov/16646090","citation_count":17,"is_preprint":false},{"pmid":"19456231","id":"PMC_19456231","title":"Fragmented tissue factor pathway inhibitor (TFPI) and TFPI C-terminal peptides eliminate serum-resistant Escherichia coli from blood cultures.","date":"2009","source":"The Journal of infectious diseases","url":"https://pubmed.ncbi.nlm.nih.gov/19456231","citation_count":17,"is_preprint":false},{"pmid":"7934956","id":"PMC_7934956","title":"Use of transgenic mouse lacI/Z mutation assays in genetic toxicology.","date":"1994","source":"Mutagenesis","url":"https://pubmed.ncbi.nlm.nih.gov/7934956","citation_count":17,"is_preprint":false},{"pmid":"35723053","id":"PMC_35723053","title":"TFPI and FXIII negatively and S100A8/A9 and Cystatin C positively correlate with D-dimer in COVID-19.","date":"2022","source":"Experimental biology and medicine (Maywood, N.J.)","url":"https://pubmed.ncbi.nlm.nih.gov/35723053","citation_count":16,"is_preprint":false},{"pmid":"38860425","id":"PMC_38860425","title":"OptoLacI: optogenetically engineered lactose operon repressor LacI responsive to light instead of IPTG.","date":"2024","source":"Nucleic acids research","url":"https://pubmed.ncbi.nlm.nih.gov/38860425","citation_count":16,"is_preprint":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":49215,"output_tokens":4464,"usd":0.107302,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":12407,"output_tokens":2507,"usd":0.062355,"stage2_stop_reason":"refusal"},"total_usd":0.334657,"stage1_batch_id":"msgbatch_0147LFpL5iCPFZF66xp23BqC","stage2_batch_id":"msgbatch_01Crtwc6eCsZh1CrnfJhY7J7","note":"batch pricing = 50% of standard","stage2_resynth":{"opus_model":"claude-opus-4-8","opus_input_tokens":12407,"opus_output_tokens":4118,"opus_usd":0.165,"opus_elapsed_seconds":111.4,"stage2_stop_reason":"end_turn"}},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 1993,\n      \"finding\": \"TFPI inhibits factor VIIa-tissue factor complexes on cell surfaces through its first and second Kunitz-type domains (KD1 inhibits FVIIa, KD2 inhibits FXa); the third Kunitz-type domain and C-terminal tail are not essential for inhibition of cell surface FVIIa-tissue factor complexes, but influence cell-surface binding affinity. Factor Xa augments TFPI anticoagulant activity equally for full-length and truncated TFPI (TFPI1-161).\",\n      \"method\": \"In vitro kinetic assay comparing full-length recombinant TFPI vs. truncated TFPI1-161 on human bladder carcinoma J82 cell surfaces; chromogenic substrate assays; displacement studies\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — in vitro reconstitution with truncation constructs and kinetic assays, single lab but multiple orthogonal methods\",\n      \"pmids\": [\"8473315\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1992,\n      \"finding\": \"TFPI (as LACI) acts as a cofactor for heparin in inhibiting tissue factor-induced coagulation; TFPI and sulfated polysaccharides act synergistically in plasma to inhibit TF-induced clotting. TFPI does not significantly regulate the intrinsic (contact) pathway of coagulation.\",\n      \"method\": \"APTT and modified prothrombin time clotting assays using LACI-depleted plasma reconstituted with purified recombinant LACI and/or heparin; comparison of various sulfated polysaccharides\",\n      \"journal\": \"Blood\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — in vitro reconstitution assay with depleted and supplemented plasma, multiple polysaccharide comparisons, single lab\",\n      \"pmids\": [\"1346095\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1995,\n      \"finding\": \"Under normal physiologic conditions, TFPI expression is restricted to megakaryocytes and endothelium of the microvasculature; it is not synthesized by normal hepatocytes or large vessel endothelium. Under pathologic conditions, adherent monocytes/macrophages express both tissue factor and TFPI.\",\n      \"method\": \"Review synthesizing immunohistochemical and cell biology studies of TFPI expression sites\",\n      \"journal\": \"Thrombosis and haemostasis\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 3 / Strong — localization established by multiple prior experimental studies summarized in review, no new primary experiment reported\",\n      \"pmids\": [\"7482419\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1996,\n      \"finding\": \"Factor Xa-TFPI binary complex formation is required to inhibit factor VIIa-tissue factor; free factor Xa-TFPI (quaternary complex precursor) inversely correlates with factor VIIa and prothrombin fragment 1+2 levels in plasma, consistent with factor Xa-TFPI regulating both factor VIIa-tissue factor and prothrombinase in vivo.\",\n      \"method\": \"ELISA-based quantification of factor VIIa, prothrombin fragment 1+2, TFPI, and factor Xa-TFPI in plasma from 145 healthy adults; novel sandwich ELISA using affinity-purified rabbit anti-human TFPI IgG and chicken anti-human factor Xa-TFPI IgY\",\n      \"journal\": \"British journal of haematology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — novel ELISA quantification in large cohort with multiple correlative analyses, single lab, observational design\",\n      \"pmids\": [\"8982054\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2009,\n      \"finding\": \"Protein S acts as a cofactor for full-length TFPI, stimulating inhibition of factor Xa by TFPI approximately 10-fold. Free protein S and full-length TFPI form a complex in plasma, confirmed by protein S immunodepletion experiments and surface plasmon resonance. TFPI levels are reduced in hereditary and acquired protein S deficiency, and concomitant TFPI deficiency substantially contributes to the hypercoagulable state.\",\n      \"method\": \"Plasma TFPI and protein S antigen measurements; calibrated automated thrombography for thrombin generation; protein S immunodepletion; surface plasmon resonance to confirm protein S-TFPI interaction\",\n      \"journal\": \"Journal of thrombosis and haemostasis : JTH\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1–2 / Strong — surface plasmon resonance plus functional thrombin generation assays plus immunodepletion, multiple orthogonal methods\",\n      \"pmids\": [\"20002538\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2009,\n      \"finding\": \"Protein S stimulates inhibition of factor Xa by full-length TFPI ~10-fold and is required for optimal TFPI anticoagulant activity; the TFPI/protein S system specifically inhibits TF pathway activation at low procoagulant stimuli. Protein S and TFPI constitute a constitutively active anticoagulant system in plasma, distinct from and cooperative with the APC pathway.\",\n      \"method\": \"Review summarizing functional plasma assays, thrombin generation experiments, and biochemical reconstitution studies from the authors' laboratory\",\n      \"journal\": \"Arteriosclerosis, thrombosis, and vascular biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — findings based on independently replicated functional reconstitution and plasma assays described in detail\",\n      \"pmids\": [\"19661488\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"TFPI inhibits MASP-2 of the lectin pathway of complement activation via its Kunitz-2 (KD2) domain, without affecting MASP-1, C1s, or C1r. This identifies TFPI as a novel selective inhibitor of MASP-2.\",\n      \"method\": \"Ex vivo lectin pathway activation assay (C4-deposition on mannan-coated plates); fluid-phase MASP-2 chromogenic activity assay; domain-mapping using recombinant TFPI and specific monoclonal antibodies against TFPI domains\",\n      \"journal\": \"European journal of immunology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1–2 / Moderate — in vitro enzymatic assay with domain-specific antibody mapping, multiple functional assays, single lab\",\n      \"pmids\": [\"25359215\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"FXa inhibition by full-length TFPI is stimulated by negatively charged phospholipids (~5–6-fold), unfractionated heparin at low concentrations (~8-fold), physiological protein S (~2–3-fold), and FV (~2–3-fold). Thrombin-activated FVa impairs TFPI inhibition of FXa. These modulatory effects require the KD3-C-terminus region of TFPI, as TFPI1-150 is insensitive to these modulators. TFPI potently inhibits FXa-catalyzed prothrombin activation in absence of FVa but not in presence of FVa.\",\n      \"method\": \"Progress curve analysis of FXa inhibition using chromogenic substrate CS11-(65); comparison of full-length TFPI vs. TFPI1-150 constructs; systematic variation of phospholipids, heparin, prothrombin, FV, FVa, protein S\",\n      \"journal\": \"Thrombosis and haemostasis\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — rigorous in vitro kinetic assays with multiple modulators and truncation constructs, single lab\",\n      \"pmids\": [\"26607136\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"TFPI directly inhibits FVIIa in a TF-dependent and phospholipid-dependent manner; the KD3-C-terminus significantly contributes to direct FVIIa inhibition (7–10-fold difference vs. constructs lacking KD3-C-terminus). KD2 also contributes to FVIIa inhibition. In the presence of FXa, a tight quaternary TF-FVIIa-TFPI-FXa complex forms requiring phospholipids and the Gla-domain of FXa but not KD3-C-terminus. Protein S stimulates TF-FVIIa inhibition by full-length TFPI (Ki reduced from 4.6 nM to 0.7 nM).\",\n      \"method\": \"Chromogenic substrate assays for FVIIa activity with relipidated or soluble TF; comparison of full-length TFPI, TFPI1-150, KD1-KD2, and KD1 constructs\",\n      \"journal\": \"Journal of thrombosis and haemostasis : JTH\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — in vitro reconstitution with multiple truncation constructs, rigorous kinetic analysis, single lab\",\n      \"pmids\": [\"23347185\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"Full-length TFPI inhibits TF:FVIIa-catalyzed FIX activation (Ki=16.7 nM) and this is stimulated 16-fold by protein S (Ki=1.0 nM). All three Kunitz domains and the C-terminus are required for optimal inhibition of FIX activation, and single Kunitz domains are poor inhibitors (Ki >800 nM). Preformed FXa:TFPI complexes rapidly and stoichiometrically inhibit FIX and FX activation by TF:FVIIa, establishing binary TFPI:FXa complex formation as the rate-limiting step.\",\n      \"method\": \"Progress curve analysis of FXa and FIXa generation with chromogenic substrates; comparison of full-length TFPI, TFPI1-150, KD1-KD2, and single domain constructs; variation of phospholipid concentration\",\n      \"journal\": \"Journal of thrombosis and haemostasis : JTH\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — rigorous in vitro kinetic reconstitution with multiple constructs and conditions, single lab\",\n      \"pmids\": [\"25163770\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"TFPI serves as a host cell receptor for TcdB from hypervirulent clade 2 Clostridioides difficile (TcdB2 and TcdB4). Cryo-EM structure of full-length TcdB4 with TFPI defined a common receptor-binding region in TcdB that is homologous to the Frizzled (FZD)-binding site in other TcdB variants. TFPI is highly expressed in intestinal glands (colonic crypts), and recombinant TFPI protects colonic epithelium from TcdB2/4.\",\n      \"method\": \"CRISPR/Cas9 genome-wide screen for TcdB4 receptor; cryo-EM structure determination of TcdB4-TFPI complex; recombinant TFPI protection assay of colonic epithelium\",\n      \"journal\": \"Cell\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — cryo-EM structure combined with CRISPR screen and functional protection assay, rigorous multi-method study in high-impact journal\",\n      \"pmids\": [\"35303428\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"TFPI is identified as a host receptor for TcdB4 (and TcdB10) from C. difficile. Intragenic micro-recombination events in the TcdB receptor-binding region determine whether TcdB variants bind TFPI or Frizzled proteins. Introduction of B4/B7-haplotype residues into TcdB1 enables dual recognition of TFPI and FZD. TcdB10 recognizes TFPI with species selectivity (chicken > mouse; not human, dog, or cattle).\",\n      \"method\": \"Genome-wide CRISPR-Cas9 screen; sequence analysis of 206 TcdB variants; mutagenesis introducing B4/B7-haplotype residues into TcdB1; cell-based binding and cytotoxicity assays\",\n      \"journal\": \"Nature communications\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — CRISPR screen confirmed by mutagenesis and functional binding assays, replicated the TFPI receptor identification from Cell paper\",\n      \"pmids\": [\"36351897\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1992,\n      \"finding\": \"Rat TFPI cDNA encodes a 302-amino acid protein with three tandem Kunitz-type inhibitor domains conserved in length across human, rabbit, and rat TFPI. TFPI mRNA is expressed as two forms (4.0 and 1.4 kb) and is abundantly expressed in heart, lung, kidney, and aortic endothelial cells in rats.\",\n      \"method\": \"cDNA cloning from rat liver cDNA library; Northern blot analysis; amino acid sequence alignment and homology analysis\",\n      \"journal\": \"Journal of biochemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — direct cDNA cloning and Northern blot characterization, single lab, structural characterization\",\n      \"pmids\": [\"1639767\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2009,\n      \"finding\": \"TFPI C-terminal peptides exhibit complement-dependent antibacterial activity against serum-resistant E. coli; C-terminal rTFPI fragments directly interact with the E. coli bacterial cell surface and kill bacteria through the complement pathway. Both complement-mediated killing and cell-surface binding are reversed by low amounts of heparin.\",\n      \"method\": \"Ex vivo blood culture killing assays with fragmented rTFPI and synthetic C-terminal TFPI peptides; serum complement-dependence assays; cell surface binding assays with reversal by heparin\",\n      \"journal\": \"The Journal of infectious diseases\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — multiple functional assays (killing, binding, heparin reversal) in ex vivo model, single lab\",\n      \"pmids\": [\"19456231\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"Protein S acts as a cofactor for full-length TFPI, stimulating FXa inhibition by TFPI. The TFPI/protein S system fails to regulate FXa generation at high TF/FVIIa concentrations but can regain activity in the presence of APC, demonstrating an intertwinement of TFPI- and APC-cofactor activities of protein S.\",\n      \"method\": \"Review summarizing plasma thrombin generation assays, purified component reconstitution experiments, and functional studies from the authors' laboratory\",\n      \"journal\": \"Thrombosis research\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — functional plasma and reconstitution data reviewed, multi-method but review format\",\n      \"pmids\": [\"22425215\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"TFPI1α (the anticoagulant protein TFPI) plays a role in driving the development of multiple drug resistance (MDR) in cancer but is not required for maintenance of the MDR state.\",\n      \"method\": \"Cancer cell line studies examining TFPI1α expression during doxorubicin resistance development (review with mechanistic discussion of primary experimental work)\",\n      \"journal\": \"Cancers\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — single lab review, mechanism not directly demonstrated in this paper, limited primary experimental detail in abstract\",\n      \"pmids\": [\"26501324\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"TFPI is a multivalent Kunitz-type serine protease inhibitor that downregulates the extrinsic coagulation pathway via a two-step mechanism: its KD2 domain first inhibits factor Xa, and the resulting binary FXa-TFPI complex then inhibits TF-FVIIa to form an inactive quaternary complex; KD1 inhibits FVIIa, KD3 and the C-terminal tail modulate FVIIa inhibition and cell-surface binding, and protein S acts as a cofactor that stimulates FXa inhibition ~10-fold by binding full-length TFPI; additionally, TFPI's KD2 inhibits MASP-2 of the lectin complement pathway, its C-terminal region has direct antibacterial activity through the complement system, and TFPI serves as a host cell receptor for clade 2 C. difficile TcdB variants in colonic crypts.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"TFPI is a multivalent Kunitz-type serine protease inhibitor that constitutively downregulates the extrinsic (tissue factor) coagulation pathway [#0, #1]. It achieves this through a two-step, FXa-dependent mechanism in which its second Kunitz domain (KD2) inhibits factor Xa, and formation of the binary FXa-TFPI complex is the rate-limiting step required for subsequent inhibition of TF-FVIIa within a tight quaternary TF-FVIIa-TFPI-FXa complex; KD1 inhibits FVIIa while the KD3-C-terminus region confers cell-surface binding and modulates FVIIa inhibition [#0, #8, #9]. Through this same machinery TFPI also inhibits TF:FVIIa-catalyzed activation of factors IX and X, with all three Kunitz domains and the C-terminus required for optimal activity [#9]. TFPI activity is tuned by multiple cofactors acting on the KD3-C-terminus: protein S forms a plasma complex with full-length TFPI and stimulates FXa inhibition ~10-fold, and negatively charged phospholipids, heparin, and FV further enhance inhibition, while thrombin-activated FVa impairs it [#4, #7, #8]. Heparin acts synergistically with TFPI to inhibit TF-induced clotting, and TFPI does not regulate the intrinsic contact pathway [#1]. Beyond coagulation, TFPI selectively inhibits MASP-2 of the lectin complement pathway via KD2, and its C-terminal region exerts complement-dependent antibacterial activity that is reversible by heparin [#6, #13]. Independently of its protease-inhibitory role, TFPI serves as a host colonic-crypt receptor for hypervirulent clade 2 Clostridioides difficile TcdB variants (TcdB2/TcdB4), binding TcdB through a region homologous to the Frizzled-binding site [#10, #11].\"\n,\n  \"teleology\": [\n    {\n      \"year\": 1992,\n      \"claim\": \"Establishing that TFPI (LACI) is a synergistic cofactor for heparin specific to the extrinsic pathway defined its position as a dedicated tissue-factor pathway regulator rather than a general anticoagulant.\",\n      \"evidence\": \"APTT/PT clotting assays with LACI-depleted plasma reconstituted with recombinant LACI and sulfated polysaccharides\",\n      \"pmids\": [\"1346095\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not resolve which domains mediate heparin synergy\", \"Mechanism of polysaccharide enhancement not defined at molecular level\"]\n    },\n    {\n      \"year\": 1992,\n      \"claim\": \"Cloning the cDNA across species defined TFPI as a three-tandem-Kunitz-domain protein and mapped broad tissue expression, providing the structural framework for later domain-function studies.\",\n      \"evidence\": \"Rat liver cDNA cloning, Northern blot, and cross-species sequence alignment\",\n      \"pmids\": [\"1639767\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Functional roles of individual domains not tested here\", \"Two mRNA forms not functionally distinguished\"]\n    },\n    {\n      \"year\": 1993,\n      \"claim\": \"Assigning KD1 to FVIIa inhibition and KD2 to FXa inhibition on cell surfaces resolved the division of labor between the Kunitz domains and showed KD3/C-terminus governs cell-surface binding rather than catalytic inhibition.\",\n      \"evidence\": \"In vitro kinetic assays comparing full-length vs. truncated TFPI1-161 on J82 carcinoma cell surfaces\",\n      \"pmids\": [\"8473315\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Quaternary complex assembly order not directly resolved\", \"Physiological cell-surface anchoring partner not identified\"]\n    },\n    {\n      \"year\": 1995,\n      \"claim\": \"Defining the restricted physiologic expression of TFPI to megakaryocytes and microvascular endothelium clarified where the inhibitor is produced and that hepatocytes are not the source.\",\n      \"evidence\": \"Review synthesizing immunohistochemical and cell-biology localization studies\",\n      \"pmids\": [\"7482419\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No new primary experiment\", \"Quantitative contribution of each source to plasma pool unresolved\"]\n    },\n    {\n      \"year\": 1996,\n      \"claim\": \"Showing that binary FXa-TFPI complex formation is required for TF-FVIIa inhibition and correlates inversely with coagulation markers in vivo extended the two-step mechanism from biochemistry into human plasma physiology.\",\n      \"evidence\": \"Novel sandwich ELISA quantification in 145 healthy adults\",\n      \"pmids\": [\"8982054\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Correlative/observational design\", \"Causal direction not established in vivo\"]\n    },\n    {\n      \"year\": 2009,\n      \"claim\": \"Identifying protein S as a plasma cofactor that stimulates FXa inhibition ~10-fold defined a constitutively active TFPI/protein S anticoagulant system and explained reduced TFPI in protein S deficiency.\",\n      \"evidence\": \"Plasma antigen measurements, calibrated thrombography, immunodepletion, and surface plasmon resonance\",\n      \"pmids\": [\"20002538\", \"19661488\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Structural basis of protein S-TFPI binding not resolved\", \"Relative in vivo weight versus APC pathway not quantified\"]\n    },\n    {\n      \"year\": 2013,\n      \"claim\": \"Demonstrating direct, TF- and phospholipid-dependent FVIIa inhibition and mapping the KD3-C-terminus contribution refined how TFPI engages the initiating protease complex and quantified protein S enhancement of TF-FVIIa inhibition.\",\n      \"evidence\": \"Chromogenic FVIIa assays comparing full-length TFPI, TFPI1-150, KD1-KD2, and KD1 constructs\",\n      \"pmids\": [\"23347185\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Single-lab in vitro reconstitution\", \"In vivo relevance of direct FVIIa inhibition vs. FXa-dependent route not weighted\"]\n    },\n    {\n      \"year\": 2014,\n      \"claim\": \"Establishing binary TFPI:FXa formation as the rate-limiting step for inhibiting TF:FVIIa-catalyzed FIX and FX activation, with all domains required, unified the multi-domain architecture into a single kinetic model.\",\n      \"evidence\": \"Progress-curve kinetics of FXa/FIXa generation with full-length and truncation constructs\",\n      \"pmids\": [\"25163770\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Cellular validation of the kinetic model limited\", \"Contribution of each cofactor to the rate-limiting step not separated\"]\n    },\n    {\n      \"year\": 2014,\n      \"claim\": \"Identifying KD2-mediated selective inhibition of MASP-2 revealed a moonlighting role for TFPI as a regulator of the lectin complement pathway, distinct from its coagulation function.\",\n      \"evidence\": \"Lectin pathway C4-deposition assays and fluid-phase MASP-2 activity with domain-specific antibodies\",\n      \"pmids\": [\"25359215\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Physiological/in vivo significance of MASP-2 inhibition not established\", \"Structural basis of KD2-MASP-2 selectivity unresolved\"]\n    },\n    {\n      \"year\": 2015,\n      \"claim\": \"Systematic dissection of cofactors (phospholipids, heparin, protein S, FV, FVa) acting through the KD3-C-terminus defined how the TFPI:FXa reaction is environmentally tuned and is antagonized by activated FVa.\",\n      \"evidence\": \"Progress-curve FXa kinetics with full-length vs. TFPI1-150 across modulator conditions\",\n      \"pmids\": [\"26607136\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Integration of competing modulators in vivo not modeled\", \"Structural mechanism of KD3-C-terminus sensitization unknown\"]\n    },\n    {\n      \"year\": 2009,\n      \"claim\": \"Showing that TFPI C-terminal peptides kill serum-resistant E. coli via the complement pathway, reversibly by heparin, extended TFPI's C-terminus into innate antibacterial defense.\",\n      \"evidence\": \"Ex vivo blood-culture killing, bacterial surface-binding, and heparin-reversal assays with C-terminal rTFPI fragments\",\n      \"pmids\": [\"19456231\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"In vivo antibacterial relevance not established\", \"Molecular target on bacterial surface not identified\"]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"Identifying TFPI as the colonic-crypt host receptor for hypervirulent clade 2 C. difficile TcdB variants, and mapping the binding site, revealed a pathogen-exploited role for TFPI unrelated to protease inhibition.\",\n      \"evidence\": \"Genome-wide CRISPR screens, cryo-EM of TcdB4-TFPI, mutagenesis defining TFPI vs. Frizzled recognition, and recombinant TFPI epithelial protection assays\",\n      \"pmids\": [\"35303428\", \"36351897\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Physiological consequence of TcdB-TFPI engagement for normal TFPI function unknown\", \"Whether toxin binding alters anticoagulant activity untested\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"How TFPI's distinct functions — coagulation inhibition, complement/MASP-2 regulation, antibacterial activity, and TcdB receptor role — are coordinated or regulated in a shared tissue context remains unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"No structural model integrating multi-functional binding surfaces\", \"Tissue-specific regulation of the different roles undefined\", \"Causal disease links beyond correlative associations not established\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0140096\", \"supporting_discovery_ids\": [0, 8, 9]},\n      {\"term_id\": \"GO:0098772\", \"supporting_discovery_ids\": [0, 1, 4, 6, 7]},\n      {\"term_id\": \"GO:0001618\", \"supporting_discovery_ids\": [10, 11]},\n      {\"term_id\": \"GO:0008289\", \"supporting_discovery_ids\": [7, 8]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005886\", \"supporting_discovery_ids\": [0, 10]},\n      {\"term_id\": \"GO:0005576\", \"supporting_discovery_ids\": [1, 4]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-109582\", \"supporting_discovery_ids\": [0, 1, 8, 9]},\n      {\"term_id\": \"R-HSA-168256\", \"supporting_discovery_ids\": [6, 13]},\n      {\"term_id\": \"R-HSA-1643685\", \"supporting_discovery_ids\": [10, 11]}\n    ],\n    \"complexes\": [\n      \"TF-FVIIa-TFPI-FXa quaternary complex\",\n      \"FXa-TFPI binary complex\",\n      \"protein S-TFPI complex\"\n    ],\n    \"partners\": [\n      \"F7\",\n      \"F10\",\n      \"F9\",\n      \"PROS1\",\n      \"MASP2\",\n      \"F5\",\n      \"TcdB\"\n    ],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win"}}