{"gene":"LGALS4","run_date":"2026-06-14T21:13:12+00:00","timeline":{"discoveries":[{"year":2005,"finding":"Galectin-4 is a major component of detergent-resistant membranes (lipid rafts) in polarized HT-29 5M12 enterocyte-like cells and is found in post-Golgi carrier vesicles. RNAi-mediated depletion of galectin-4 causes intracellular accumulation of apical (but not basolateral) membrane markers and alters DRM association of apical proteins. Sulfatides with long chain-hydroxylated fatty acids (enriched in DRMs) were identified as high-affinity ligands for galectin-4, supporting a model in which galectin-4/sulfatide interaction clusters lipid rafts for apical membrane delivery.","method":"Retrovirus-mediated RNAi knockdown, detergent-resistant membrane fractionation, post-Golgi vesicle isolation, ligand binding assays","journal":"The Journal of cell biology","confidence":"High","confidence_rationale":"Tier 2 / Strong — reciprocal fractionation, RNAi loss-of-function with defined apical trafficking phenotype, ligand identification; multiple orthogonal methods in a focused study","pmids":["15883199"],"is_preprint":false},{"year":2007,"finding":"Galectin-4 binds cholesterol 3-sulfate (which lacks a beta-galactoside moiety), a property unique within the galectin family. Site-directed mutagenesis (R45A) identified Arg45 in the N-terminal CRD as indispensable for cholesterol 3-sulfate recognition. Gel filtration and chemical cross-linking showed that galectin-4 exists as dimers, enhancing avidity for this ligand. Cholesterol 3-sulfate and sulfatide co-exist with galectin-4 in detergent-insoluble fractions of porcine esophagus and intestine, suggesting both are endogenous in vivo ligands.","method":"Site-directed mutagenesis, gel filtration, chemical cross-linking, detergent-insoluble fractionation","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 1 / Moderate — active-site mutagenesis combined with biochemical dimerization assays and in vivo tissue fractionation, single lab but multiple orthogonal methods","pmids":["17545668"],"is_preprint":false},{"year":2013,"finding":"Galectin-4 is tyrosine-phosphorylated by Src family kinases; the C-terminal peptide YVQI is essential for this phosphorylation and binds the SH2 domains of Src and SHP2. Phosphorylation status controls externalization of galectin-4: mutant galectin-4 lacking the C-terminal YVQI peptide is not efficiently externalized. MUC1 from NUGC-4 cells binds galectin-4, and externalization of the MUC1–galectin-4 complex increases under hyperphosphorylated conditions, suggesting galectin-4 acts intracellularly as an adaptor that modulates glycoprotein trafficking.","method":"Pervanadate treatment, Src co-transfection/phosphorylation assay, SH2 domain binding assay, immunofluorescence, C-terminal deletion mutant transfection","journal":"Glycobiology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — co-transfection phosphorylation assay, mutant rescue, SH2 pulldown, and localization; single lab with multiple methods","pmids":["24013903"],"is_preprint":false},{"year":2014,"finding":"Galectin-4 mediates apical transcytosis of basolateral proteins (exemplified by transferrin receptor, TfR) in epithelial cells lacking the basolateral adaptor AP-1B. Mutation of the N-glycosylation site N727 on TfR or knockdown of galectin-4 blocks TfR transcytosis to apical recycling endosomes and the apical plasma membrane, instead routing TfR to lysosomes for degradation.","method":"N-glycosylation site mutagenesis, siRNA knockdown, cell fractionation/trafficking assays in RPE, KPT, and AP-1B-knockdown MDCK cells","journal":"Journal of cell science","confidence":"High","confidence_rationale":"Tier 2 / Moderate — mutagenesis of glycan site combined with RNAi knockdown and defined trafficking phenotype (lysosomal degradation vs. apical delivery); multiple cell models","pmids":["25179596"],"is_preprint":false},{"year":2012,"finding":"Galectin-4, released by neurons but not oligodendrocytes in vitro, retards oligodendrocyte maturation and inhibits myelination. Treatment of immature oligodendrocytes with galectin-4 causes a subset to revert to a morphologically less complex progenitor stage with increased proliferation. Addition of galectin-4 or anti-galectin-4 antibodies to dorsal root ganglion neuron–oligodendrocyte co-cultures inhibits myelination. Galectin-4-reactive sites are transiently expressed on processes of premyelinating oligodendrocytes (but not neurons), and reduced endogenous galectin-4 release correlates with the onset of myelination.","method":"In vitro oligodendrocyte treatment, DRG–OLG co-culture myelination assay, immunofluorescence localization, proliferation assays","journal":"Glia","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — gain-of-function (exogenous Gal-4) and loss-of-function (blocking antibody) with defined myelination phenotype; single lab, multiple complementary assays","pmids":["22431161"],"is_preprint":false},{"year":2022,"finding":"Galectin-4-deficient (Lgals4-KO) mice show no significant defect in cortical myelin composition, organization, microstructure, or function assessed by electrophysiology and locomotion, indicating that galectin-4 is dispensable for cortical myelination in vivo (negative result).","method":"Lgals4-KO mouse model, Western blot, immunohistochemistry, in-depth image analysis, in vivo and ex vivo electrophysiology, locomotion assays","journal":"Cells","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — genetic KO with multiple orthogonal readouts (biochemical, morphological, electrophysiological); single lab; result is a rigorous negative","pmids":["36359880"],"is_preprint":false},{"year":2016,"finding":"Full-length structural model of human galectin-4 was determined using X-ray crystallography and small-/wide-angle X-ray scattering, revealing the structural role of the linker peptide connecting the two CRDs and dynamic characteristics of carbohydrate recognition. The linker peptide confers flexibility and modulates inter-domain communication.","method":"X-ray crystallography, SAXS/WAXS, molecular dynamics simulations, differential scanning fluorimetry","journal":"Scientific reports","confidence":"High","confidence_rationale":"Tier 1 / Moderate — crystal structure combined with solution scattering and MD simulations; multiple complementary structural methods in one study","pmids":["27642006"],"is_preprint":false},{"year":2013,"finding":"Galectin-4 knockdown in HT-29 colorectal cancer cells increases cell proliferation and activates NF-κB and STAT3 signaling with up-regulation of IL-6, demonstrating that galectin-4 suppresses the IL-6/NF-κB/STAT3 signaling axis. This was further confirmed by enhanced xenograft tumor growth in vivo upon shRNA-mediated galectin-4 silencing.","method":"shRNA knockdown, RT-PCR, qPCR array, Western blotting, immunofluorescence, xenograft assay","journal":"Cellular oncology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — RNAi loss-of-function with defined signaling pathway phenotype confirmed in vivo; single lab, multiple methods","pmids":["23378274"],"is_preprint":false},{"year":2013,"finding":"Galectin-4 inhibits migration of pancreatic cancer cells in vitro (scratch assay) and reduces metastasis formation in vivo in a zebrafish model. Galectin-4 accumulates at membrane contact sites between neighboring cells, suggesting it acts as a cell-surface adhesion molecule to prevent tumor cell dissemination. An additional cytosolic function inhibiting migration (mechanism unidentified) is also indicated.","method":"In vitro scratch assay, zebrafish in vivo metastasis model, immunofluorescence localization","journal":"PloS one","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — defined migration and metastasis phenotypes with two independent models (in vitro + zebrafish); single lab","pmids":["23824659"],"is_preprint":false},{"year":2023,"finding":"Extracellular galectin-4 secreted by pancreatic ductal adenocarcinoma cells promotes T-cell apoptosis by binding N-glycosylation residues on CD3ε/δ, mediating immune evasion. In vivo, reduced galectin-4 expression increased T-cell infiltration and prolonged survival in immunocompetent but not immunodeficient RAG1-/- mice, confirming adaptive immune system dependence.","method":"Orthotopic transplantation, RAG1-/- mouse model, co-culture T-cell apoptosis assay, single-cell RNA-sequencing, binding assay (CD3ε/δ N-glycan)","journal":"Cancer immunology research","confidence":"High","confidence_rationale":"Tier 2 / Strong — in vivo genetic epistasis (RAG1 KO), co-culture mechanistic assay identifying binding partner (CD3ε/δ N-glycans), and scRNA-seq; multiple orthogonal methods in one study","pmids":["36478037"],"is_preprint":false},{"year":2023,"finding":"Galectin-4 on the surface of gastric cancer cells physically interacts with CD44 and c-MET via its carbohydrate-binding domain, maintaining their expression and activation. CRISPR/Cas9-mediated galectin-4 knockout reduced activated c-MET and CD44 levels and attenuated peritoneal metastasis in mice.","method":"CRISPR/Cas9 knockout, proximity ligation assay, Western blotting, siRNA knockdown, mouse peritoneal metastasis model, immunohistochemistry","journal":"Gastric cancer","confidence":"High","confidence_rationale":"Tier 2 / Moderate — CRISPR KO combined with proximity ligation assay identifying binding partners (CD44, c-MET) and in vivo metastasis phenotype; multiple orthogonal methods","pmids":["36695981"],"is_preprint":false},{"year":2024,"finding":"Galectin-4 antimicrobial activity is primarily mediated by its C-terminal domain (Gal-4C). Gal-4C but not the N-terminal domain (Gal-4N) forms dimers, binds ABO(H) blood group antigens with higher affinity, and displays more potent killing of microbes expressing blood group-like antigens. The full-length Gal-4 also exists as a dimer via Gal-4C dimerization, which functionally renders Gal-4N bivalent, yet Gal-4C retains superior antimicrobial activity.","method":"Glycan microarray, microbial binding/killing assays, chemical cross-linking (dimer detection), domain-specific recombinant protein assays","journal":"Molecular & cellular proteomics","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — domain-specific recombinant proteins with multiple binding and antimicrobial assays; single lab","pmids":["38490531"],"is_preprint":false},{"year":2017,"finding":"Surface-bound galectin-4 on colorectal cancer cells suppresses cell proliferation and chemokine secretion. Neutralization of surface-bound galectin-4 with antibody increases proliferation and upregulates 29 genes in inflammation signaling pathways. Conversely, addition of recombinant galectin-4 to galectin-4-negative colorectal cancer cells increases p27 and decreases cyclin D1 and c-Myc, causing cell cycle arrest and apoptosis.","method":"Antibody neutralization, recombinant protein treatment, gene expression profiling, Western blotting","journal":"Tumour biology","confidence":"Medium","confidence_rationale":"Tier 3 / Moderate — antibody neutralization and recombinant protein gain-of-function with defined signaling readouts; single lab, complementary approaches","pmids":["28345468"],"is_preprint":false},{"year":2021,"finding":"Galectin-4 treatment of primary human osteoarthritis chondrocytes induces pro-degradative and pro-inflammatory gene expression (IL-1β, MMP-13) through NF-κB pathway activation (phosphorylation of p65 at Ser536) in a carbohydrate-inhibitable manner. In 3D pellet cultures, galectin-4 causes morphological and biochemical signs of cartilage degradation.","method":"Primary human chondrocyte culture, recombinant Gal-4 treatment, RT-qPCR, transcriptome analysis, Western blot for p65 phosphorylation, p65 inhibitor experiments, 3D pellet culture","journal":"Histochemistry and cell biology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — carbohydrate inhibition confirms lectin-dependent mechanism; multiple readouts including pathway inhibitors; single lab","pmids":["34846578"],"is_preprint":false},{"year":2025,"finding":"Galectin-4 enhances MHC-I surface expression on dendritic cells, promoting CD8+ T-cell responses against tumors and viral infections. Lgals4-KO mice show impaired antigen-MHC-I complex surface expression on DCs and consequently deficient CD8+ T-cell responses, enhanced syngeneic tumor growth, and diminished antiviral CD8+ T-cell responses against LCMV. The defect is DC-intrinsic, not CD8+ T cell-intrinsic. Exogenous Gal-4 administration enhances cancer vaccine and PD-1 blockade efficacy.","method":"Lgals4-KO mouse model, syngeneic tumor models, LCMV infection, flow cytometry (MHC-I surface expression on DCs), adoptive transfer to distinguish cell-intrinsic defects, cancer vaccine/PD-1 blockade therapeutic experiments","journal":"Molecular therapy","confidence":"High","confidence_rationale":"Tier 2 / Moderate — genetic KO with multiple defined phenotypes, mechanistic identification (MHC-I on DCs), epistasis distinguishing T cell vs DC intrinsic defect; multiple models","pmids":["40589087"],"is_preprint":false},{"year":2026,"finding":"Galectin-4 associates with multiple receptor tyrosine kinases (RTKs) including c-MET and EGFR on the gastric cancer cell surface via its carbohydrate recognition domain. In galectin-4 KO cells, tyrosine phosphorylation of proximal RTKs is markedly reduced and c-MET surface expression decreases. Hyperphosphorylation promotes colocalization of galectin-4 with tyrosine-phosphorylated proteins. Surface plasmon resonance showed galectin-4 binds tyrosine-phosphorylated molecules via its CRD; overexpression of B3GALT5 (a glycosyltransferase producing lacto-series glycans) alters PY protein and galectin-4 localization, suggesting competitive regulation of galectin-4 binding by glycosylation vs. tyrosine phosphorylation.","method":"Antibody array, proximity ligation assay, surface plasmon resonance, galectin-4 KO (CRISPR), B3GALT5 overexpression, Western blotting","journal":"Scientific reports","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — SPR binding assay plus KO and overexpression experiments with multiple RTK readouts; single lab, multiple orthogonal methods","pmids":["41991671"],"is_preprint":false},{"year":2025,"finding":"Lgals4-KO mice exhibit altered intestinal commensal microbiota, deficient memory formation, and impaired hippocampal LTP in vivo and ex vivo. In vitro, Lgals4-KO neurons show reduced activation of AMPA receptors and CaMKII upon chemically induced LTP. KO mice also display lower hippocampal dendritic spine density, shorter spine length, and increased postsynaptic density area, linking gut galectin-4 (through microbiota modulation) to hippocampal synaptic plasticity.","method":"Lgals4-KO mouse, 16S rRNA gut microbiota sequencing, behavioral tests, in vivo/ex vivo LTP electrophysiology, immunofluorescence, Western blot (AMPA receptor, CaMKII), RNA-seq, Golgi-Cox staining, electron microscopy","journal":"Biological psychiatry","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — genetic KO with highly diverse orthogonal readouts (electrophysiology, spine morphology, molecular signaling); single lab; microbiota-brain link is correlational but synaptic phenotypes are directly measured","pmids":["41101578"],"is_preprint":false},{"year":2025,"finding":"Galectin-4 inhibits proteasomal degradation of lactate dehydrogenase A (LDHA) by competitively reducing TRIM28 binding to LDHA, thereby enhancing glycolysis. This promotes HIF-1α-mediated CXCL6 expression, which drives accumulation of PD-L1+ tumor-associated neutrophils and impairs CD8+ T-cell cytotoxicity, conferring resistance to anti-PD-L1/bevacizumab therapy in HCC.","method":"scRNA-seq, co-culture system, CyTOF, genetic knockdown, pharmacological inhibition, prospective clinical cohort, preclinical HCC mouse models","journal":"Gut","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — mechanistic pathway (Gal-4/LDHA/TRIM28/HIF-1α/CXCL6) identified with genetic and pharmacological perturbation in multiple preclinical models; single lab","pmids":["41057233"],"is_preprint":false},{"year":2016,"finding":"Galectin-4 overexpression in Rcho-1 rat trophoblast cells inhibits cell enlargement and promotes cell-cell adhesion during differentiation without affecting trophoblast-specific markers or MMP-9 activity. Autophagy inhibitors (3-MA, Bafilomycin A1) prevent the normal downregulation of galectin-4 during trophoblast differentiation, placing autophagy upstream of galectin-4 expression regulation.","method":"Overexpression in Rcho-1 cells, autophagy inhibitor treatment (3-MA, Bafilomycin A1), Western blot, in vitro differentiation assay","journal":"Scientific reports","confidence":"Low","confidence_rationale":"Tier 3 / Weak — overexpression and pharmacological inhibitor experiments in single model cell line; indirect epistasis via inhibitors only","pmids":["27572741"],"is_preprint":false},{"year":2024,"finding":"B3GALT5 overexpression (introducing lacto-series GSLs with β1,3-linked galactose) reduces galectin-4 colocalization with flotillin-2 in lipid rafts and decreases galectin-4-dependent tumorigenic signaling (reduced activated AKT). GSL synthase inhibitor (PPMP) similarly disrupts galectin-4 raft localization, suggesting that GSL composition of microdomains regulates galectin-4 localization to lipid rafts.","method":"B3GALT5 overexpression, mass spectrometry glycan profiling, GSL synthase inhibitor treatment, co-localization immunofluorescence (galectin-4/flotillin-2), mouse peritoneal metastasis model","journal":"Glycobiology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — glycan profiling plus genetic and pharmacological manipulation with defined localization and functional readouts; single lab, multiple methods","pmids":["39163480"],"is_preprint":false},{"year":2023,"finding":"Galectin-4 treatment of M2 macrophages enhances their immunostimulatory gene expression, upregulating antiviral immune response genes, and increases antibody production and antiviral CD4+ T-cell responses (but not CD8+ T-cell responses) against LCMV in vivo. This enhancement is dependent on TLR7 stimulation or viral infection context.","method":"Recombinant Gal-4 treatment of M1/M2 macrophages, gene expression analysis, TLR7 stimulation, LCMV infection model, in vivo antibody/T-cell response measurement","journal":"Journal of leukocyte biology","confidence":"Low","confidence_rationale":"Tier 3 / Weak — exogenous recombinant protein treatment without identification of specific receptor/binding partner on macrophages; single lab","pmids":["36822160"],"is_preprint":false}],"current_model":"Galectin-4 is a tandem-repeat β-galactoside-binding lectin (with structurally and functionally distinct N- and C-terminal CRDs) that operates both intracellularly and extracellularly: intracellularly it localizes to detergent-resistant lipid rafts and post-Golgi vesicles, where its interaction with sulfatides/cholesterol 3-sulfate (mediated by Arg45) clusters lipid rafts to drive apical membrane trafficking in polarized epithelia; it is externalized via a Src-family-kinase-dependent, YVQI-motif-mediated phosphorylation mechanism; extracellularly it acts as a glycan cross-linker that binds CD44, c-MET, EGFR, and other receptor tyrosine kinases through its CRD to sustain RTK phosphorylation and surface expression, binds CD3ε/δ N-glycans on T cells to induce apoptosis and immune evasion, enhances MHC-I surface expression on dendritic cells to promote CD8+ T-cell responses, inhibits LDHA proteasomal degradation (by competing with TRIM28) to enhance glycolysis and drive HIF-1α/CXCL6-mediated immunosuppression in cancer, mediates basolateral-to-apical transcytosis of N-glycosylated cargo, and suppresses NF-κB/STAT3/IL-6 pro-tumorigenic signaling; its C-terminal domain is the primary mediator of dimerization and antimicrobial activity against blood-group-mimicking pathogens."},"narrative":{"mechanistic_narrative":"LGALS4 encodes galectin-4, a tandem-repeat β-galactoside-binding lectin with two structurally and functionally distinct carbohydrate-recognition domains (CRDs) joined by a flexible linker that modulates inter-domain communication and carbohydrate recognition [PMID:27642006], which acts both intracellularly as a membrane-trafficking organizer and extracellularly as a glycan cross-linker on cell surfaces. Intracellularly, galectin-4 is a major component of detergent-resistant lipid rafts and post-Golgi carrier vesicles, where its high-affinity binding to sulfatides—and, uniquely among galectins, to cholesterol 3-sulfate via Arg45 of the N-terminal CRD—clusters lipid rafts to drive apical membrane delivery in polarized epithelia [PMID:15883199, PMID:17545668]; it also mediates apical transcytosis of N-glycosylated basolateral cargo such as the transferrin receptor, rerouting cargo away from lysosomal degradation [PMID:25179596]. Its raft localization depends on glycosphingolipid composition, and is externalized through a Src-family-kinase-dependent mechanism requiring a C-terminal YVQI motif that binds Src and SHP2 SH2 domains [PMID:24013903, PMID:39163480]. Extracellularly, surface-bound galectin-4 cross-links N-glycans on receptor tyrosine kinases including c-MET and EGFR, and on CD44, sustaining their phosphorylation and surface expression to promote gastric cancer metastasis [PMID:36695981, PMID:41991671]. In immunity, galectin-4 enhances MHC-I surface expression on dendritic cells to support CD8+ T-cell responses against tumors and viral infection [PMID:40589087], yet tumor-secreted galectin-4 also drives immune evasion by binding CD3ε/δ N-glycans to induce T-cell apoptosis [PMID:36478037] and by stabilizing LDHA against TRIM28-mediated proteasomal degradation to enhance glycolysis and HIF-1α/CXCL6 immunosuppression [PMID:41057233]. The C-terminal domain mediates dimerization and antimicrobial killing of blood-group-antigen-bearing microbes [PMID:38490531]. Loss-of-function studies reveal additional roles in suppressing IL-6/NF-κB/STAT3 pro-tumorigenic signaling in colorectal cancer [PMID:23378274] and, via gut microbiota modulation, in hippocampal synaptic plasticity and memory [PMID:41101578].","teleology":[{"year":2005,"claim":"Established galectin-4 as an intracellular organizer of apical membrane trafficking, answering how lectin-lipid interactions could direct polarized delivery.","evidence":"RNAi knockdown, detergent-resistant membrane fractionation, post-Golgi vesicle isolation, and ligand binding in HT-29 enterocyte-like cells","pmids":["15883199"],"confidence":"High","gaps":["Did not resolve the precise glycan/lipid coincidence that triggers raft clustering","Mechanism of vesicle scission/delivery downstream of clustering unresolved"]},{"year":2007,"claim":"Defined the molecular basis of galectin-4's unique non-β-galactoside ligand recognition, identifying Arg45 in the N-terminal CRD as required for cholesterol 3-sulfate binding and showing dimerization enhances avidity.","evidence":"Site-directed mutagenesis (R45A), gel filtration, chemical cross-linking, and tissue detergent-insoluble fractionation in porcine esophagus/intestine","pmids":["17545668"],"confidence":"High","gaps":["In vivo functional consequence of Arg45-mediated binding not tested by mutation in cells/animals","Relative contribution of sulfatide vs cholesterol 3-sulfate to raft clustering unresolved"]},{"year":2012,"claim":"Implicated secreted neuronal galectin-4 as a negative regulator of oligodendrocyte maturation and myelination in vitro.","evidence":"Exogenous Gal-4 gain-of-function and blocking-antibody loss-of-function in oligodendrocyte and DRG–OLG co-cultures","pmids":["22431161"],"confidence":"Medium","gaps":["No receptor/binding partner on oligodendrocytes identified","In vivo relevance not established at this stage"]},{"year":2013,"claim":"Identified the externalization mechanism, linking Src-family tyrosine phosphorylation of a C-terminal YVQI motif to unconventional secretion and glycoprotein cargo trafficking.","evidence":"Pervanadate/Src co-transfection phosphorylation assays, SH2-domain binding, and C-terminal deletion mutant externalization assays","pmids":["24013903"],"confidence":"Medium","gaps":["Exact phosphosite(s) and stoichiometry not mapped","How phosphorylation mechanistically couples to membrane exit is unresolved"]},{"year":2013,"claim":"Revealed a tumor-suppressive role in colorectal cancer through suppression of the IL-6/NF-κB/STAT3 axis, confirmed in vivo.","evidence":"shRNA knockdown with signaling readouts and xenograft tumor growth assays in HT-29 cells","pmids":["23378274"],"confidence":"Medium","gaps":["Direct molecular target linking galectin-4 to NF-κB/STAT3 not identified","Intracellular vs extracellular site of action not separated"]},{"year":2013,"claim":"Showed galectin-4 acts as a cell-surface adhesion molecule restraining pancreatic cancer migration and metastasis.","evidence":"In vitro scratch assay, zebrafish metastasis model, and immunofluorescence localization to cell contact sites","pmids":["23824659"],"confidence":"Medium","gaps":["Cytosolic anti-migratory mechanism left unidentified","Surface binding partner mediating adhesion not defined"]},{"year":2014,"claim":"Established galectin-4 as a glycan-dependent mediator of basolateral-to-apical transcytosis, rescuing cargo from lysosomal degradation in AP-1B-deficient epithelia.","evidence":"N-glycosylation site mutagenesis of TfR and galectin-4 siRNA in RPE, KPT, and AP-1B-knockdown MDCK cells","pmids":["25179596"],"confidence":"High","gaps":["Generality across cargo beyond TfR not fully mapped","Machinery coupling galectin-4 to transcytotic vesicles unresolved"]},{"year":2016,"claim":"Provided a full-length structural model defining the linker peptide's role in inter-domain flexibility and dynamic carbohydrate recognition.","evidence":"X-ray crystallography, SAXS/WAXS, MD simulations, and differential scanning fluorimetry of human galectin-4","pmids":["27642006"],"confidence":"High","gaps":["No co-structure with physiological ligands such as sulfatide","Conformational basis of CRD functional asymmetry not fully explained"]},{"year":2016,"claim":"Linked galectin-4 to trophoblast differentiation and placed autophagy upstream of its expression regulation.","evidence":"Overexpression in Rcho-1 cells and autophagy inhibitor (3-MA, Bafilomycin A1) treatment","pmids":["27572741"],"confidence":"Low","gaps":["Indirect epistasis via inhibitors only; no direct genetic test","Single model cell line; physiological relevance unconfirmed"]},{"year":2017,"claim":"Demonstrated that surface-bound galectin-4 enforces cell-cycle arrest and dampens inflammatory chemokine signaling in colorectal cancer.","evidence":"Antibody neutralization and recombinant protein treatment with gene expression profiling and cell-cycle protein readouts","pmids":["28345468"],"confidence":"Medium","gaps":["Receptor mediating surface signaling not identified","Direct link from glycan binding to p27/cyclin D1 changes unresolved"]},{"year":2022,"claim":"A rigorous in vivo negative result showed galectin-4 is dispensable for cortical myelination, qualifying the earlier in vitro myelination model.","evidence":"Lgals4-KO mouse with biochemical, morphological, and electrophysiological readouts","pmids":["36359880"],"confidence":"Medium","gaps":["Does not exclude compensatory redundancy by other galectins","Peripheral or developmental-timing myelination effects not fully excluded"]},{"year":2023,"claim":"Identified surface galectin-4's RTK cross-linking activity, showing it binds CD44 and c-MET via the CRD to sustain their activation and drive gastric cancer peritoneal metastasis.","evidence":"CRISPR/Cas9 knockout, proximity ligation assay, and mouse peritoneal metastasis model","pmids":["36695981"],"confidence":"High","gaps":["Specific glycan epitopes on CD44/c-MET not mapped","Whether cross-linking directly activates vs stabilizes the receptors unresolved"]},{"year":2023,"claim":"Established tumor-secreted galectin-4 as a driver of immune evasion through CD3ε/δ N-glycan-dependent T-cell apoptosis.","evidence":"Orthotopic transplantation, RAG1-/- epistasis, T-cell apoptosis co-culture, scRNA-seq, and N-glycan binding assay in PDAC","pmids":["36478037"],"confidence":"High","gaps":["Downstream apoptotic signaling in T cells not detailed","Reconciliation with galectin-4's pro-immune DC role context-dependent"]},{"year":2023,"claim":"Showed exogenous galectin-4 reprograms M2 macrophages toward antiviral, immunostimulatory states in a TLR7/infection-dependent manner.","evidence":"Recombinant Gal-4 treatment of macrophages with gene expression and LCMV in vivo readouts","pmids":["36822160"],"confidence":"Low","gaps":["No macrophage receptor/binding partner identified for galectin-4","Single lab, recombinant-protein-only gain-of-function"]},{"year":2024,"claim":"Assigned the C-terminal domain as the primary mediator of dimerization and antimicrobial killing of blood-group-antigen-bearing microbes.","evidence":"Glycan microarray, microbial binding/killing assays, and chemical cross-linking with domain-specific recombinant proteins","pmids":["38490531"],"confidence":"Medium","gaps":["Mechanism of microbial killing (membrane disruption vs agglutination) not defined","In vivo antimicrobial role not tested"]},{"year":2024,"claim":"Demonstrated that glycosphingolipid composition controls galectin-4 raft localization and downstream tumorigenic AKT signaling.","evidence":"B3GALT5 overexpression, glycan mass spectrometry, GSL synthase inhibitor (PPMP), flotillin-2 colocalization, and metastasis model","pmids":["39163480"],"confidence":"Medium","gaps":["Direct competition between lacto-series GSLs and endogenous ligands not biochemically quantified","Link from raft localization to AKT activation not fully mechanistic"]},{"year":2025,"claim":"Revealed a DC-intrinsic, immune-promoting role: galectin-4 enhances MHC-I surface expression on dendritic cells to license CD8+ T-cell antitumor and antiviral responses.","evidence":"Lgals4-KO mice, syngeneic tumor and LCMV models, flow cytometry, adoptive transfer, and vaccine/PD-1 blockade therapeutic experiments","pmids":["40589087"],"confidence":"High","gaps":["Molecular step by which galectin-4 boosts MHC-I surface display not defined","Reconciliation with tumor-secreted immunosuppressive roles is context-dependent"]},{"year":2025,"claim":"Connected galectin-4 to metabolic reprogramming of the tumor microenvironment by stabilizing LDHA against TRIM28-mediated degradation, driving glycolysis and HIF-1α/CXCL6 immunosuppression.","evidence":"scRNA-seq, co-culture, CyTOF, genetic/pharmacological perturbation, clinical cohort, and HCC mouse models","pmids":["41057233"],"confidence":"Medium","gaps":["Whether this LDHA stabilization is intracellular galectin-4 directly competing with TRIM28 needs structural confirmation","Single lab"]},{"year":2025,"claim":"Linked gut galectin-4, via microbiota modulation, to hippocampal synaptic plasticity and memory.","evidence":"Lgals4-KO mice with 16S microbiota sequencing, behavior, in vivo/ex vivo LTP, spine morphology, and AMPA/CaMKII molecular readouts","pmids":["41101578"],"confidence":"Medium","gaps":["Microbiota-to-brain link is correlational; causal mediator not isolated","Direct neuronal substrate of galectin-4 not identified"]},{"year":2026,"claim":"Broadened the RTK cross-linking model, showing galectin-4 binds multiple RTKs (c-MET, EGFR) and tyrosine-phosphorylated proteins via its CRD, with glycosylation and phosphorylation competitively regulating its surface binding.","evidence":"Antibody array, proximity ligation assay, SPR, CRISPR KO, and B3GALT5 overexpression in gastric cancer cells","pmids":["41991671"],"confidence":"Medium","gaps":["Direct binding to phosphotyrosine vs phospho-altered glycans not fully disentangled","Structural basis of competition between glycan and phosphorylation unresolved"]},{"year":null,"claim":"How galectin-4's opposing pro-immune (DC MHC-I enhancement, antimicrobial) and immunosuppressive (T-cell apoptosis, LDHA/HIF-1α) activities are selected in a given tissue or tumor context remains unresolved.","evidence":"","pmids":[],"confidence":"Medium","gaps":["No unifying model reconciling context-dependent immune outcomes","The decision rules governing intracellular trafficking vs externalization vs surface cross-linking are not integrated","Receptors on immune cells beyond CD3ε/δ largely unidentified"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0008289","term_label":"lipid binding","supporting_discovery_ids":[0,1]},{"term_id":"GO:0060090","term_label":"molecular adaptor activity","supporting_discovery_ids":[2,3]},{"term_id":"GO:0098631","term_label":"cell adhesion mediator activity","supporting_discovery_ids":[8]},{"term_id":"GO:0090729","term_label":"toxin activity","supporting_discovery_ids":[11]}],"localization":[{"term_id":"GO:0005886","term_label":"plasma membrane","supporting_discovery_ids":[10,15,19]},{"term_id":"GO:0031410","term_label":"cytoplasmic vesicle","supporting_discovery_ids":[0]},{"term_id":"GO:0005794","term_label":"Golgi apparatus","supporting_discovery_ids":[0]},{"term_id":"GO:0005768","term_label":"endosome","supporting_discovery_ids":[3]},{"term_id":"GO:0005576","term_label":"extracellular region","supporting_discovery_ids":[2,9,12]},{"term_id":"GO:0005829","term_label":"cytosol","supporting_discovery_ids":[8]}],"pathway":[{"term_id":"R-HSA-9609507","term_label":"Protein localization","supporting_discovery_ids":[0,3]},{"term_id":"R-HSA-168256","term_label":"Immune System","supporting_discovery_ids":[9,14]},{"term_id":"R-HSA-162582","term_label":"Signal Transduction","supporting_discovery_ids":[7,10,15]},{"term_id":"R-HSA-1643685","term_label":"Disease","supporting_discovery_ids":[7,9,10,17]},{"term_id":"R-HSA-5653656","term_label":"Vesicle-mediated transport","supporting_discovery_ids":[0,3]}],"complexes":[],"partners":["CD44","MET","EGFR","CD3E","CD3D","SRC","PTPN11","LDHA"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"P56470","full_name":"Galectin-4","aliases":["Antigen NY-CO-27","L-36 lactose-binding protein","L36LBP","Lactose-binding lectin 4"],"length_aa":323,"mass_kda":35.9,"function":"Galectin that binds lactose and a related range of sugars. May be involved in the assembly of adherens junctions","subcellular_location":"","url":"https://www.uniprot.org/uniprotkb/P56470/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/LGALS4","classification":"Not Classified","n_dependent_lines":6,"n_total_lines":1208,"dependency_fraction":0.004966887417218543},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[],"url":"https://opencell.sf.czbiohub.org/search/LGALS4","total_profiled":1310},"omim":[{"mim_id":"613842","title":"GDNF-INDUCIBLE ZINC FINGER PROTEIN 1; GZF1","url":"https://www.omim.org/entry/613842"},{"mim_id":"606099","title":"LECTIN, GALACTOSIDE-BINDING, SOLUBLE, 8; LGALS8","url":"https://www.omim.org/entry/606099"},{"mim_id":"602518","title":"LECTIN, GALACTOSIDE-BINDING, SOLUBLE, 4; LGALS4","url":"https://www.omim.org/entry/602518"},{"mim_id":"600615","title":"LECTIN, GALACTOSIDE-BINDING, SOLUBLE, 7; LGALS7","url":"https://www.omim.org/entry/600615"},{"mim_id":"300670","title":"SPANX FAMILY, MEMBER D; SPANXD","url":"https://www.omim.org/entry/300670"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Uncertain","locations":[{"location":"Plasma membrane","reliability":"Uncertain"}],"tissue_specificity":"Tissue enriched","tissue_distribution":"Detected in many","driving_tissues":[{"tissue":"intestine","ntpm":1827.2}],"url":"https://www.proteinatlas.org/search/LGALS4"},"hgnc":{"alias_symbol":["GAL4"],"prev_symbol":[]},"alphafold":{"accession":"P56470","domains":[{"cath_id":"2.60.120.200","chopping":"8-149","consensus_level":"high","plddt":95.6994,"start":8,"end":149},{"cath_id":"2.60.120.200","chopping":"186-321","consensus_level":"high","plddt":95.5614,"start":186,"end":321}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/P56470","model_url":"https://alphafold.ebi.ac.uk/files/AF-P56470-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-P56470-F1-predicted_aligned_error_v6.png","plddt_mean":89.62},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=LGALS4","jax_strain_url":"https://www.jax.org/strain/search?query=LGALS4"},"sequence":{"accession":"P56470","fasta_url":"https://rest.uniprot.org/uniprotkb/P56470.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/P56470/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/P56470"}},"corpus_meta":[{"pmid":"15883199","id":"PMC_15883199","title":"Galectin-4 and sulfatides in apical membrane trafficking in enterocyte-like cells.","date":"2005","source":"The Journal of cell biology","url":"https://pubmed.ncbi.nlm.nih.gov/15883199","citation_count":213,"is_preprint":false},{"pmid":"7852431","id":"PMC_7852431","title":"Galectin-8. 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RNAi-mediated depletion of galectin-4 causes intracellular accumulation of apical (but not basolateral) membrane markers and alters DRM association of apical proteins. Sulfatides with long chain-hydroxylated fatty acids (enriched in DRMs) were identified as high-affinity ligands for galectin-4, supporting a model in which galectin-4/sulfatide interaction clusters lipid rafts for apical membrane delivery.\",\n      \"method\": \"Retrovirus-mediated RNAi knockdown, detergent-resistant membrane fractionation, post-Golgi vesicle isolation, ligand binding assays\",\n      \"journal\": \"The Journal of cell biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — reciprocal fractionation, RNAi loss-of-function with defined apical trafficking phenotype, ligand identification; multiple orthogonal methods in a focused study\",\n      \"pmids\": [\"15883199\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2007,\n      \"finding\": \"Galectin-4 binds cholesterol 3-sulfate (which lacks a beta-galactoside moiety), a property unique within the galectin family. Site-directed mutagenesis (R45A) identified Arg45 in the N-terminal CRD as indispensable for cholesterol 3-sulfate recognition. Gel filtration and chemical cross-linking showed that galectin-4 exists as dimers, enhancing avidity for this ligand. Cholesterol 3-sulfate and sulfatide co-exist with galectin-4 in detergent-insoluble fractions of porcine esophagus and intestine, suggesting both are endogenous in vivo ligands.\",\n      \"method\": \"Site-directed mutagenesis, gel filtration, chemical cross-linking, detergent-insoluble fractionation\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — active-site mutagenesis combined with biochemical dimerization assays and in vivo tissue fractionation, single lab but multiple orthogonal methods\",\n      \"pmids\": [\"17545668\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"Galectin-4 is tyrosine-phosphorylated by Src family kinases; the C-terminal peptide YVQI is essential for this phosphorylation and binds the SH2 domains of Src and SHP2. Phosphorylation status controls externalization of galectin-4: mutant galectin-4 lacking the C-terminal YVQI peptide is not efficiently externalized. MUC1 from NUGC-4 cells binds galectin-4, and externalization of the MUC1–galectin-4 complex increases under hyperphosphorylated conditions, suggesting galectin-4 acts intracellularly as an adaptor that modulates glycoprotein trafficking.\",\n      \"method\": \"Pervanadate treatment, Src co-transfection/phosphorylation assay, SH2 domain binding assay, immunofluorescence, C-terminal deletion mutant transfection\",\n      \"journal\": \"Glycobiology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — co-transfection phosphorylation assay, mutant rescue, SH2 pulldown, and localization; single lab with multiple methods\",\n      \"pmids\": [\"24013903\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"Galectin-4 mediates apical transcytosis of basolateral proteins (exemplified by transferrin receptor, TfR) in epithelial cells lacking the basolateral adaptor AP-1B. Mutation of the N-glycosylation site N727 on TfR or knockdown of galectin-4 blocks TfR transcytosis to apical recycling endosomes and the apical plasma membrane, instead routing TfR to lysosomes for degradation.\",\n      \"method\": \"N-glycosylation site mutagenesis, siRNA knockdown, cell fractionation/trafficking assays in RPE, KPT, and AP-1B-knockdown MDCK cells\",\n      \"journal\": \"Journal of cell science\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — mutagenesis of glycan site combined with RNAi knockdown and defined trafficking phenotype (lysosomal degradation vs. apical delivery); multiple cell models\",\n      \"pmids\": [\"25179596\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"Galectin-4, released by neurons but not oligodendrocytes in vitro, retards oligodendrocyte maturation and inhibits myelination. Treatment of immature oligodendrocytes with galectin-4 causes a subset to revert to a morphologically less complex progenitor stage with increased proliferation. Addition of galectin-4 or anti-galectin-4 antibodies to dorsal root ganglion neuron–oligodendrocyte co-cultures inhibits myelination. Galectin-4-reactive sites are transiently expressed on processes of premyelinating oligodendrocytes (but not neurons), and reduced endogenous galectin-4 release correlates with the onset of myelination.\",\n      \"method\": \"In vitro oligodendrocyte treatment, DRG–OLG co-culture myelination assay, immunofluorescence localization, proliferation assays\",\n      \"journal\": \"Glia\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — gain-of-function (exogenous Gal-4) and loss-of-function (blocking antibody) with defined myelination phenotype; single lab, multiple complementary assays\",\n      \"pmids\": [\"22431161\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"Galectin-4-deficient (Lgals4-KO) mice show no significant defect in cortical myelin composition, organization, microstructure, or function assessed by electrophysiology and locomotion, indicating that galectin-4 is dispensable for cortical myelination in vivo (negative result).\",\n      \"method\": \"Lgals4-KO mouse model, Western blot, immunohistochemistry, in-depth image analysis, in vivo and ex vivo electrophysiology, locomotion assays\",\n      \"journal\": \"Cells\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — genetic KO with multiple orthogonal readouts (biochemical, morphological, electrophysiological); single lab; result is a rigorous negative\",\n      \"pmids\": [\"36359880\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"Full-length structural model of human galectin-4 was determined using X-ray crystallography and small-/wide-angle X-ray scattering, revealing the structural role of the linker peptide connecting the two CRDs and dynamic characteristics of carbohydrate recognition. The linker peptide confers flexibility and modulates inter-domain communication.\",\n      \"method\": \"X-ray crystallography, SAXS/WAXS, molecular dynamics simulations, differential scanning fluorimetry\",\n      \"journal\": \"Scientific reports\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — crystal structure combined with solution scattering and MD simulations; multiple complementary structural methods in one study\",\n      \"pmids\": [\"27642006\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"Galectin-4 knockdown in HT-29 colorectal cancer cells increases cell proliferation and activates NF-κB and STAT3 signaling with up-regulation of IL-6, demonstrating that galectin-4 suppresses the IL-6/NF-κB/STAT3 signaling axis. This was further confirmed by enhanced xenograft tumor growth in vivo upon shRNA-mediated galectin-4 silencing.\",\n      \"method\": \"shRNA knockdown, RT-PCR, qPCR array, Western blotting, immunofluorescence, xenograft assay\",\n      \"journal\": \"Cellular oncology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — RNAi loss-of-function with defined signaling pathway phenotype confirmed in vivo; single lab, multiple methods\",\n      \"pmids\": [\"23378274\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"Galectin-4 inhibits migration of pancreatic cancer cells in vitro (scratch assay) and reduces metastasis formation in vivo in a zebrafish model. Galectin-4 accumulates at membrane contact sites between neighboring cells, suggesting it acts as a cell-surface adhesion molecule to prevent tumor cell dissemination. An additional cytosolic function inhibiting migration (mechanism unidentified) is also indicated.\",\n      \"method\": \"In vitro scratch assay, zebrafish in vivo metastasis model, immunofluorescence localization\",\n      \"journal\": \"PloS one\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — defined migration and metastasis phenotypes with two independent models (in vitro + zebrafish); single lab\",\n      \"pmids\": [\"23824659\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"Extracellular galectin-4 secreted by pancreatic ductal adenocarcinoma cells promotes T-cell apoptosis by binding N-glycosylation residues on CD3ε/δ, mediating immune evasion. In vivo, reduced galectin-4 expression increased T-cell infiltration and prolonged survival in immunocompetent but not immunodeficient RAG1-/- mice, confirming adaptive immune system dependence.\",\n      \"method\": \"Orthotopic transplantation, RAG1-/- mouse model, co-culture T-cell apoptosis assay, single-cell RNA-sequencing, binding assay (CD3ε/δ N-glycan)\",\n      \"journal\": \"Cancer immunology research\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — in vivo genetic epistasis (RAG1 KO), co-culture mechanistic assay identifying binding partner (CD3ε/δ N-glycans), and scRNA-seq; multiple orthogonal methods in one study\",\n      \"pmids\": [\"36478037\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"Galectin-4 on the surface of gastric cancer cells physically interacts with CD44 and c-MET via its carbohydrate-binding domain, maintaining their expression and activation. CRISPR/Cas9-mediated galectin-4 knockout reduced activated c-MET and CD44 levels and attenuated peritoneal metastasis in mice.\",\n      \"method\": \"CRISPR/Cas9 knockout, proximity ligation assay, Western blotting, siRNA knockdown, mouse peritoneal metastasis model, immunohistochemistry\",\n      \"journal\": \"Gastric cancer\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — CRISPR KO combined with proximity ligation assay identifying binding partners (CD44, c-MET) and in vivo metastasis phenotype; multiple orthogonal methods\",\n      \"pmids\": [\"36695981\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"Galectin-4 antimicrobial activity is primarily mediated by its C-terminal domain (Gal-4C). Gal-4C but not the N-terminal domain (Gal-4N) forms dimers, binds ABO(H) blood group antigens with higher affinity, and displays more potent killing of microbes expressing blood group-like antigens. The full-length Gal-4 also exists as a dimer via Gal-4C dimerization, which functionally renders Gal-4N bivalent, yet Gal-4C retains superior antimicrobial activity.\",\n      \"method\": \"Glycan microarray, microbial binding/killing assays, chemical cross-linking (dimer detection), domain-specific recombinant protein assays\",\n      \"journal\": \"Molecular & cellular proteomics\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — domain-specific recombinant proteins with multiple binding and antimicrobial assays; single lab\",\n      \"pmids\": [\"38490531\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"Surface-bound galectin-4 on colorectal cancer cells suppresses cell proliferation and chemokine secretion. Neutralization of surface-bound galectin-4 with antibody increases proliferation and upregulates 29 genes in inflammation signaling pathways. Conversely, addition of recombinant galectin-4 to galectin-4-negative colorectal cancer cells increases p27 and decreases cyclin D1 and c-Myc, causing cell cycle arrest and apoptosis.\",\n      \"method\": \"Antibody neutralization, recombinant protein treatment, gene expression profiling, Western blotting\",\n      \"journal\": \"Tumour biology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 3 / Moderate — antibody neutralization and recombinant protein gain-of-function with defined signaling readouts; single lab, complementary approaches\",\n      \"pmids\": [\"28345468\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"Galectin-4 treatment of primary human osteoarthritis chondrocytes induces pro-degradative and pro-inflammatory gene expression (IL-1β, MMP-13) through NF-κB pathway activation (phosphorylation of p65 at Ser536) in a carbohydrate-inhibitable manner. In 3D pellet cultures, galectin-4 causes morphological and biochemical signs of cartilage degradation.\",\n      \"method\": \"Primary human chondrocyte culture, recombinant Gal-4 treatment, RT-qPCR, transcriptome analysis, Western blot for p65 phosphorylation, p65 inhibitor experiments, 3D pellet culture\",\n      \"journal\": \"Histochemistry and cell biology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — carbohydrate inhibition confirms lectin-dependent mechanism; multiple readouts including pathway inhibitors; single lab\",\n      \"pmids\": [\"34846578\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"Galectin-4 enhances MHC-I surface expression on dendritic cells, promoting CD8+ T-cell responses against tumors and viral infections. Lgals4-KO mice show impaired antigen-MHC-I complex surface expression on DCs and consequently deficient CD8+ T-cell responses, enhanced syngeneic tumor growth, and diminished antiviral CD8+ T-cell responses against LCMV. The defect is DC-intrinsic, not CD8+ T cell-intrinsic. Exogenous Gal-4 administration enhances cancer vaccine and PD-1 blockade efficacy.\",\n      \"method\": \"Lgals4-KO mouse model, syngeneic tumor models, LCMV infection, flow cytometry (MHC-I surface expression on DCs), adoptive transfer to distinguish cell-intrinsic defects, cancer vaccine/PD-1 blockade therapeutic experiments\",\n      \"journal\": \"Molecular therapy\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — genetic KO with multiple defined phenotypes, mechanistic identification (MHC-I on DCs), epistasis distinguishing T cell vs DC intrinsic defect; multiple models\",\n      \"pmids\": [\"40589087\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2026,\n      \"finding\": \"Galectin-4 associates with multiple receptor tyrosine kinases (RTKs) including c-MET and EGFR on the gastric cancer cell surface via its carbohydrate recognition domain. In galectin-4 KO cells, tyrosine phosphorylation of proximal RTKs is markedly reduced and c-MET surface expression decreases. Hyperphosphorylation promotes colocalization of galectin-4 with tyrosine-phosphorylated proteins. Surface plasmon resonance showed galectin-4 binds tyrosine-phosphorylated molecules via its CRD; overexpression of B3GALT5 (a glycosyltransferase producing lacto-series glycans) alters PY protein and galectin-4 localization, suggesting competitive regulation of galectin-4 binding by glycosylation vs. tyrosine phosphorylation.\",\n      \"method\": \"Antibody array, proximity ligation assay, surface plasmon resonance, galectin-4 KO (CRISPR), B3GALT5 overexpression, Western blotting\",\n      \"journal\": \"Scientific reports\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — SPR binding assay plus KO and overexpression experiments with multiple RTK readouts; single lab, multiple orthogonal methods\",\n      \"pmids\": [\"41991671\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"Lgals4-KO mice exhibit altered intestinal commensal microbiota, deficient memory formation, and impaired hippocampal LTP in vivo and ex vivo. In vitro, Lgals4-KO neurons show reduced activation of AMPA receptors and CaMKII upon chemically induced LTP. KO mice also display lower hippocampal dendritic spine density, shorter spine length, and increased postsynaptic density area, linking gut galectin-4 (through microbiota modulation) to hippocampal synaptic plasticity.\",\n      \"method\": \"Lgals4-KO mouse, 16S rRNA gut microbiota sequencing, behavioral tests, in vivo/ex vivo LTP electrophysiology, immunofluorescence, Western blot (AMPA receptor, CaMKII), RNA-seq, Golgi-Cox staining, electron microscopy\",\n      \"journal\": \"Biological psychiatry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — genetic KO with highly diverse orthogonal readouts (electrophysiology, spine morphology, molecular signaling); single lab; microbiota-brain link is correlational but synaptic phenotypes are directly measured\",\n      \"pmids\": [\"41101578\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"Galectin-4 inhibits proteasomal degradation of lactate dehydrogenase A (LDHA) by competitively reducing TRIM28 binding to LDHA, thereby enhancing glycolysis. This promotes HIF-1α-mediated CXCL6 expression, which drives accumulation of PD-L1+ tumor-associated neutrophils and impairs CD8+ T-cell cytotoxicity, conferring resistance to anti-PD-L1/bevacizumab therapy in HCC.\",\n      \"method\": \"scRNA-seq, co-culture system, CyTOF, genetic knockdown, pharmacological inhibition, prospective clinical cohort, preclinical HCC mouse models\",\n      \"journal\": \"Gut\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — mechanistic pathway (Gal-4/LDHA/TRIM28/HIF-1α/CXCL6) identified with genetic and pharmacological perturbation in multiple preclinical models; single lab\",\n      \"pmids\": [\"41057233\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"Galectin-4 overexpression in Rcho-1 rat trophoblast cells inhibits cell enlargement and promotes cell-cell adhesion during differentiation without affecting trophoblast-specific markers or MMP-9 activity. Autophagy inhibitors (3-MA, Bafilomycin A1) prevent the normal downregulation of galectin-4 during trophoblast differentiation, placing autophagy upstream of galectin-4 expression regulation.\",\n      \"method\": \"Overexpression in Rcho-1 cells, autophagy inhibitor treatment (3-MA, Bafilomycin A1), Western blot, in vitro differentiation assay\",\n      \"journal\": \"Scientific reports\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — overexpression and pharmacological inhibitor experiments in single model cell line; indirect epistasis via inhibitors only\",\n      \"pmids\": [\"27572741\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"B3GALT5 overexpression (introducing lacto-series GSLs with β1,3-linked galactose) reduces galectin-4 colocalization with flotillin-2 in lipid rafts and decreases galectin-4-dependent tumorigenic signaling (reduced activated AKT). GSL synthase inhibitor (PPMP) similarly disrupts galectin-4 raft localization, suggesting that GSL composition of microdomains regulates galectin-4 localization to lipid rafts.\",\n      \"method\": \"B3GALT5 overexpression, mass spectrometry glycan profiling, GSL synthase inhibitor treatment, co-localization immunofluorescence (galectin-4/flotillin-2), mouse peritoneal metastasis model\",\n      \"journal\": \"Glycobiology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — glycan profiling plus genetic and pharmacological manipulation with defined localization and functional readouts; single lab, multiple methods\",\n      \"pmids\": [\"39163480\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"Galectin-4 treatment of M2 macrophages enhances their immunostimulatory gene expression, upregulating antiviral immune response genes, and increases antibody production and antiviral CD4+ T-cell responses (but not CD8+ T-cell responses) against LCMV in vivo. This enhancement is dependent on TLR7 stimulation or viral infection context.\",\n      \"method\": \"Recombinant Gal-4 treatment of M1/M2 macrophages, gene expression analysis, TLR7 stimulation, LCMV infection model, in vivo antibody/T-cell response measurement\",\n      \"journal\": \"Journal of leukocyte biology\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — exogenous recombinant protein treatment without identification of specific receptor/binding partner on macrophages; single lab\",\n      \"pmids\": [\"36822160\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"Galectin-4 is a tandem-repeat β-galactoside-binding lectin (with structurally and functionally distinct N- and C-terminal CRDs) that operates both intracellularly and extracellularly: intracellularly it localizes to detergent-resistant lipid rafts and post-Golgi vesicles, where its interaction with sulfatides/cholesterol 3-sulfate (mediated by Arg45) clusters lipid rafts to drive apical membrane trafficking in polarized epithelia; it is externalized via a Src-family-kinase-dependent, YVQI-motif-mediated phosphorylation mechanism; extracellularly it acts as a glycan cross-linker that binds CD44, c-MET, EGFR, and other receptor tyrosine kinases through its CRD to sustain RTK phosphorylation and surface expression, binds CD3ε/δ N-glycans on T cells to induce apoptosis and immune evasion, enhances MHC-I surface expression on dendritic cells to promote CD8+ T-cell responses, inhibits LDHA proteasomal degradation (by competing with TRIM28) to enhance glycolysis and drive HIF-1α/CXCL6-mediated immunosuppression in cancer, mediates basolateral-to-apical transcytosis of N-glycosylated cargo, and suppresses NF-κB/STAT3/IL-6 pro-tumorigenic signaling; its C-terminal domain is the primary mediator of dimerization and antimicrobial activity against blood-group-mimicking pathogens.\"\n}\n```","stage2_raw":"```json\n{\n  \"mechanistic_narrative\": \"LGALS4 encodes galectin-4, a tandem-repeat β-galactoside-binding lectin with two structurally and functionally distinct carbohydrate-recognition domains (CRDs) joined by a flexible linker that modulates inter-domain communication and carbohydrate recognition [#6], which acts both intracellularly as a membrane-trafficking organizer and extracellularly as a glycan cross-linker on cell surfaces. Intracellularly, galectin-4 is a major component of detergent-resistant lipid rafts and post-Golgi carrier vesicles, where its high-affinity binding to sulfatides—and, uniquely among galectins, to cholesterol 3-sulfate via Arg45 of the N-terminal CRD—clusters lipid rafts to drive apical membrane delivery in polarized epithelia [#0, #1]; it also mediates apical transcytosis of N-glycosylated basolateral cargo such as the transferrin receptor, rerouting cargo away from lysosomal degradation [#3]. Its raft localization depends on glycosphingolipid composition, and is externalized through a Src-family-kinase-dependent mechanism requiring a C-terminal YVQI motif that binds Src and SHP2 SH2 domains [#2, #19]. Extracellularly, surface-bound galectin-4 cross-links N-glycans on receptor tyrosine kinases including c-MET and EGFR, and on CD44, sustaining their phosphorylation and surface expression to promote gastric cancer metastasis [#10, #15]. In immunity, galectin-4 enhances MHC-I surface expression on dendritic cells to support CD8+ T-cell responses against tumors and viral infection [#14], yet tumor-secreted galectin-4 also drives immune evasion by binding CD3ε/δ N-glycans to induce T-cell apoptosis [#9] and by stabilizing LDHA against TRIM28-mediated proteasomal degradation to enhance glycolysis and HIF-1α/CXCL6 immunosuppression [#17]. The C-terminal domain mediates dimerization and antimicrobial killing of blood-group-antigen-bearing microbes [#11]. Loss-of-function studies reveal additional roles in suppressing IL-6/NF-κB/STAT3 pro-tumorigenic signaling in colorectal cancer [#7] and, via gut microbiota modulation, in hippocampal synaptic plasticity and memory [#16].\",\n  \"teleology\": [\n    {\n      \"year\": 2005,\n      \"claim\": \"Established galectin-4 as an intracellular organizer of apical membrane trafficking, answering how lectin-lipid interactions could direct polarized delivery.\",\n      \"evidence\": \"RNAi knockdown, detergent-resistant membrane fractionation, post-Golgi vesicle isolation, and ligand binding in HT-29 enterocyte-like cells\",\n      \"pmids\": [\"15883199\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not resolve the precise glycan/lipid coincidence that triggers raft clustering\", \"Mechanism of vesicle scission/delivery downstream of clustering unresolved\"]\n    },\n    {\n      \"year\": 2007,\n      \"claim\": \"Defined the molecular basis of galectin-4's unique non-β-galactoside ligand recognition, identifying Arg45 in the N-terminal CRD as required for cholesterol 3-sulfate binding and showing dimerization enhances avidity.\",\n      \"evidence\": \"Site-directed mutagenesis (R45A), gel filtration, chemical cross-linking, and tissue detergent-insoluble fractionation in porcine esophagus/intestine\",\n      \"pmids\": [\"17545668\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"In vivo functional consequence of Arg45-mediated binding not tested by mutation in cells/animals\", \"Relative contribution of sulfatide vs cholesterol 3-sulfate to raft clustering unresolved\"]\n    },\n    {\n      \"year\": 2012,\n      \"claim\": \"Implicated secreted neuronal galectin-4 as a negative regulator of oligodendrocyte maturation and myelination in vitro.\",\n      \"evidence\": \"Exogenous Gal-4 gain-of-function and blocking-antibody loss-of-function in oligodendrocyte and DRG–OLG co-cultures\",\n      \"pmids\": [\"22431161\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No receptor/binding partner on oligodendrocytes identified\", \"In vivo relevance not established at this stage\"]\n    },\n    {\n      \"year\": 2013,\n      \"claim\": \"Identified the externalization mechanism, linking Src-family tyrosine phosphorylation of a C-terminal YVQI motif to unconventional secretion and glycoprotein cargo trafficking.\",\n      \"evidence\": \"Pervanadate/Src co-transfection phosphorylation assays, SH2-domain binding, and C-terminal deletion mutant externalization assays\",\n      \"pmids\": [\"24013903\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Exact phosphosite(s) and stoichiometry not mapped\", \"How phosphorylation mechanistically couples to membrane exit is unresolved\"]\n    },\n    {\n      \"year\": 2013,\n      \"claim\": \"Revealed a tumor-suppressive role in colorectal cancer through suppression of the IL-6/NF-κB/STAT3 axis, confirmed in vivo.\",\n      \"evidence\": \"shRNA knockdown with signaling readouts and xenograft tumor growth assays in HT-29 cells\",\n      \"pmids\": [\"23378274\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct molecular target linking galectin-4 to NF-κB/STAT3 not identified\", \"Intracellular vs extracellular site of action not separated\"]\n    },\n    {\n      \"year\": 2013,\n      \"claim\": \"Showed galectin-4 acts as a cell-surface adhesion molecule restraining pancreatic cancer migration and metastasis.\",\n      \"evidence\": \"In vitro scratch assay, zebrafish metastasis model, and immunofluorescence localization to cell contact sites\",\n      \"pmids\": [\"23824659\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Cytosolic anti-migratory mechanism left unidentified\", \"Surface binding partner mediating adhesion not defined\"]\n    },\n    {\n      \"year\": 2014,\n      \"claim\": \"Established galectin-4 as a glycan-dependent mediator of basolateral-to-apical transcytosis, rescuing cargo from lysosomal degradation in AP-1B-deficient epithelia.\",\n      \"evidence\": \"N-glycosylation site mutagenesis of TfR and galectin-4 siRNA in RPE, KPT, and AP-1B-knockdown MDCK cells\",\n      \"pmids\": [\"25179596\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Generality across cargo beyond TfR not fully mapped\", \"Machinery coupling galectin-4 to transcytotic vesicles unresolved\"]\n    },\n    {\n      \"year\": 2016,\n      \"claim\": \"Provided a full-length structural model defining the linker peptide's role in inter-domain flexibility and dynamic carbohydrate recognition.\",\n      \"evidence\": \"X-ray crystallography, SAXS/WAXS, MD simulations, and differential scanning fluorimetry of human galectin-4\",\n      \"pmids\": [\"27642006\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"No co-structure with physiological ligands such as sulfatide\", \"Conformational basis of CRD functional asymmetry not fully explained\"]\n    },\n    {\n      \"year\": 2016,\n      \"claim\": \"Linked galectin-4 to trophoblast differentiation and placed autophagy upstream of its expression regulation.\",\n      \"evidence\": \"Overexpression in Rcho-1 cells and autophagy inhibitor (3-MA, Bafilomycin A1) treatment\",\n      \"pmids\": [\"27572741\"],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"Indirect epistasis via inhibitors only; no direct genetic test\", \"Single model cell line; physiological relevance unconfirmed\"]\n    },\n    {\n      \"year\": 2017,\n      \"claim\": \"Demonstrated that surface-bound galectin-4 enforces cell-cycle arrest and dampens inflammatory chemokine signaling in colorectal cancer.\",\n      \"evidence\": \"Antibody neutralization and recombinant protein treatment with gene expression profiling and cell-cycle protein readouts\",\n      \"pmids\": [\"28345468\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Receptor mediating surface signaling not identified\", \"Direct link from glycan binding to p27/cyclin D1 changes unresolved\"]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"A rigorous in vivo negative result showed galectin-4 is dispensable for cortical myelination, qualifying the earlier in vitro myelination model.\",\n      \"evidence\": \"Lgals4-KO mouse with biochemical, morphological, and electrophysiological readouts\",\n      \"pmids\": [\"36359880\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Does not exclude compensatory redundancy by other galectins\", \"Peripheral or developmental-timing myelination effects not fully excluded\"]\n    },\n    {\n      \"year\": 2023,\n      \"claim\": \"Identified surface galectin-4's RTK cross-linking activity, showing it binds CD44 and c-MET via the CRD to sustain their activation and drive gastric cancer peritoneal metastasis.\",\n      \"evidence\": \"CRISPR/Cas9 knockout, proximity ligation assay, and mouse peritoneal metastasis model\",\n      \"pmids\": [\"36695981\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Specific glycan epitopes on CD44/c-MET not mapped\", \"Whether cross-linking directly activates vs stabilizes the receptors unresolved\"]\n    },\n    {\n      \"year\": 2023,\n      \"claim\": \"Established tumor-secreted galectin-4 as a driver of immune evasion through CD3ε/δ N-glycan-dependent T-cell apoptosis.\",\n      \"evidence\": \"Orthotopic transplantation, RAG1-/- epistasis, T-cell apoptosis co-culture, scRNA-seq, and N-glycan binding assay in PDAC\",\n      \"pmids\": [\"36478037\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Downstream apoptotic signaling in T cells not detailed\", \"Reconciliation with galectin-4's pro-immune DC role context-dependent\"]\n    },\n    {\n      \"year\": 2023,\n      \"claim\": \"Showed exogenous galectin-4 reprograms M2 macrophages toward antiviral, immunostimulatory states in a TLR7/infection-dependent manner.\",\n      \"evidence\": \"Recombinant Gal-4 treatment of macrophages with gene expression and LCMV in vivo readouts\",\n      \"pmids\": [\"36822160\"],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"No macrophage receptor/binding partner identified for galectin-4\", \"Single lab, recombinant-protein-only gain-of-function\"]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"Assigned the C-terminal domain as the primary mediator of dimerization and antimicrobial killing of blood-group-antigen-bearing microbes.\",\n      \"evidence\": \"Glycan microarray, microbial binding/killing assays, and chemical cross-linking with domain-specific recombinant proteins\",\n      \"pmids\": [\"38490531\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Mechanism of microbial killing (membrane disruption vs agglutination) not defined\", \"In vivo antimicrobial role not tested\"]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"Demonstrated that glycosphingolipid composition controls galectin-4 raft localization and downstream tumorigenic AKT signaling.\",\n      \"evidence\": \"B3GALT5 overexpression, glycan mass spectrometry, GSL synthase inhibitor (PPMP), flotillin-2 colocalization, and metastasis model\",\n      \"pmids\": [\"39163480\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct competition between lacto-series GSLs and endogenous ligands not biochemically quantified\", \"Link from raft localization to AKT activation not fully mechanistic\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Revealed a DC-intrinsic, immune-promoting role: galectin-4 enhances MHC-I surface expression on dendritic cells to license CD8+ T-cell antitumor and antiviral responses.\",\n      \"evidence\": \"Lgals4-KO mice, syngeneic tumor and LCMV models, flow cytometry, adoptive transfer, and vaccine/PD-1 blockade therapeutic experiments\",\n      \"pmids\": [\"40589087\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Molecular step by which galectin-4 boosts MHC-I surface display not defined\", \"Reconciliation with tumor-secreted immunosuppressive roles is context-dependent\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Connected galectin-4 to metabolic reprogramming of the tumor microenvironment by stabilizing LDHA against TRIM28-mediated degradation, driving glycolysis and HIF-1α/CXCL6 immunosuppression.\",\n      \"evidence\": \"scRNA-seq, co-culture, CyTOF, genetic/pharmacological perturbation, clinical cohort, and HCC mouse models\",\n      \"pmids\": [\"41057233\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Whether this LDHA stabilization is intracellular galectin-4 directly competing with TRIM28 needs structural confirmation\", \"Single lab\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Linked gut galectin-4, via microbiota modulation, to hippocampal synaptic plasticity and memory.\",\n      \"evidence\": \"Lgals4-KO mice with 16S microbiota sequencing, behavior, in vivo/ex vivo LTP, spine morphology, and AMPA/CaMKII molecular readouts\",\n      \"pmids\": [\"41101578\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Microbiota-to-brain link is correlational; causal mediator not isolated\", \"Direct neuronal substrate of galectin-4 not identified\"]\n    },\n    {\n      \"year\": 2026,\n      \"claim\": \"Broadened the RTK cross-linking model, showing galectin-4 binds multiple RTKs (c-MET, EGFR) and tyrosine-phosphorylated proteins via its CRD, with glycosylation and phosphorylation competitively regulating its surface binding.\",\n      \"evidence\": \"Antibody array, proximity ligation assay, SPR, CRISPR KO, and B3GALT5 overexpression in gastric cancer cells\",\n      \"pmids\": [\"41991671\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct binding to phosphotyrosine vs phospho-altered glycans not fully disentangled\", \"Structural basis of competition between glycan and phosphorylation unresolved\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"How galectin-4's opposing pro-immune (DC MHC-I enhancement, antimicrobial) and immunosuppressive (T-cell apoptosis, LDHA/HIF-1α) activities are selected in a given tissue or tumor context remains unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No unifying model reconciling context-dependent immune outcomes\", \"The decision rules governing intracellular trafficking vs externalization vs surface cross-linking are not integrated\", \"Receptors on immune cells beyond CD3ε/δ largely unidentified\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0030246\", \"supporting_discovery_ids\": [0, 1, 10, 11, 15]},\n      {\"term_id\": \"GO:0008289\", \"supporting_discovery_ids\": [0, 1]},\n      {\"term_id\": \"GO:0060090\", \"supporting_discovery_ids\": [2, 3]},\n      {\"term_id\": \"GO:0098631\", \"supporting_discovery_ids\": [8]},\n      {\"term_id\": \"GO:0090729\", \"supporting_discovery_ids\": [11]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005886\", \"supporting_discovery_ids\": [10, 15, 19]},\n      {\"term_id\": \"GO:0031410\", \"supporting_discovery_ids\": [0]},\n      {\"term_id\": \"GO:0005794\", \"supporting_discovery_ids\": [0]},\n      {\"term_id\": \"GO:0005768\", \"supporting_discovery_ids\": [3]},\n      {\"term_id\": \"GO:0005576\", \"supporting_discovery_ids\": [2, 9, 12]},\n      {\"term_id\": \"GO:0005829\", \"supporting_discovery_ids\": [8]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-9609507\", \"supporting_discovery_ids\": [0, 3]},\n      {\"term_id\": \"R-HSA-168256\", \"supporting_discovery_ids\": [9, 14]},\n      {\"term_id\": \"R-HSA-162582\", \"supporting_discovery_ids\": [7, 10, 15]},\n      {\"term_id\": \"R-HSA-1643685\", \"supporting_discovery_ids\": [7, 9, 10, 17]},\n      {\"term_id\": \"R-HSA-5653656\", \"supporting_discovery_ids\": [0, 3]}\n    ],\n    \"complexes\": [],\n    \"partners\": [\"CD44\", \"MET\", \"EGFR\", \"CD3E\", \"CD3D\", \"SRC\", \"PTPN11\", \"LDHA\"],\n    \"other_free_text\": []\n  }\n}\n```","audit_flag":null,"evaluation":{"pairwise":"win"}}