{"gene":"CRLF3","run_date":"2026-06-09T22:57:19","timeline":{"discoveries":[{"year":2021,"finding":"CRLF3 loss-of-function in patient-derived hiPSC-forebrain cerebral organoids causes neuronal differentiation, survival, and maturation defects through impaired RhoA signaling, identifying CRLF3 as a regulator of neuronal maturation downstream of RhoA.","method":"hiPSC-derived cerebral organoids from NF1-TGD patients with reduced CRLF3 expression; phenotypic rescue experiments; pathway analysis","journal":"Cell reports","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — loss-of-function in patient-derived organoids with defined cellular phenotype and pathway placement (RhoA signaling), single lab with multiple readouts","pmids":["34233200"],"is_preprint":false},{"year":2017,"finding":"Insect (Tribolium castaneum) ortholog of CRLF3 is required for erythropoietin (Epo)-mediated neuroprotection: RNAi knockdown of CRLF3 abolished the ability of recombinant human Epo and non-erythropoietic splice variant EV-3 to prevent serum-deprivation- and hypoxia-induced apoptosis in primary neuronal cultures.","method":"In vitro RNAi knockdown in primary Tribolium brain neuron cultures; apoptosis assay with recombinant human Epo and EV-3 treatment","journal":"Frontiers in molecular neuroscience","confidence":"Medium","confidence_rationale":"Tier 2 / Strong — replicated across two insect species (Tribolium and Locusta) by independent studies, consistent RNAi loss-of-function with defined neuroprotective phenotype","pmids":["28769759"],"is_preprint":false},{"year":2019,"finding":"CRLF3 ortholog in Locusta migratoria mediates erythropoietin-induced neuroprotection: soaking RNAi knockdown of Lm-crlf3 abolished the protective effect of recombinant human Epo against hypoxia-induced apoptosis in primary locust brain neuron cultures.","method":"Soaking RNAi in primary Locusta migratoria brain cell cultures; hypoxia-induced apoptosis assay with recombinant human Epo","journal":"Frontiers in molecular neuroscience","confidence":"Medium","confidence_rationale":"Tier 2 / Strong — replicates the Tribolium finding in a second insect species (hemimetabolous), consistent loss-of-function phenotype","pmids":["31680856"],"is_preprint":false},{"year":2021,"finding":"CRLF3 mediates neuroprotection by an endogenous conserved cytokine present in locust hemolymph: RNAi knockdown of crlf3 in both Locusta migratoria and Tribolium castaneum neurons abolished the neuroprotective effect of locust hemolymph serum against hypoxia-induced apoptosis.","method":"RNAi knockdown of crlf3 in primary locust and Tribolium neuron/hemocyte cultures; cell survival assay with locust hemolymph serum supplementation","journal":"Frontiers in physiology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — loss-of-function in two species with consistent phenotype, single lab, identifies endogenous ligand context","pmids":["33897456"],"is_preprint":false},{"year":2022,"finding":"CRLF3 deficiency in mice leads to a 25–48% reduction in platelet count without affecting other blood cell lineages, and Crlf3−/− preplatelets show increased microtubule stability associated with increased microtubule glutamylation via CRLF3 interaction with key members of the Hippo pathway, identifying CRLF3 as a regulator of the preplatelet-to-platelet maturation (fission) step.","method":"Crlf3 knockout mouse model; platelet counting; electron microscopy of preplatelets; microtubule stability assays; co-immunoprecipitation with Hippo pathway members; JAK2 V617F essential thrombocythemia mouse model cross","journal":"Blood","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — clean KO mouse with lineage-specific phenotype and mechanistic interaction (Hippo pathway co-IP), single lab","pmids":["35051265"],"is_preprint":false},{"year":2022,"finding":"CRLF3 is required for early hematopoiesis in zebrafish: crlf3 mutants generated by genome editing show significant reduction in primitive hematopoiesis and early definitive hematopoiesis, affecting multiple lineages via decreased early progenitors.","method":"CRISPR/genome editing to generate crlf3 mutant zebrafish; in situ hybridization and cell lineage markers for hematopoietic progenitors","journal":"Frontiers in immunology","confidence":"Medium","confidence_rationale":"Tier 2 / Weak — clean genetic KO in zebrafish with defined hematopoietic phenotype, single lab, single model system","pmids":["35795682"],"is_preprint":false},{"year":2023,"finding":"Human CRLF3 functions as a receptor for the non-erythropoietic Epo splice variant EV-3 mediating neuroprotection: CRLF3 knockout iPSC-derived neurons failed to be protected by EV-3 against rotenone-induced apoptosis, and this was associated with differential expression of pro- and anti-apoptotic genes.","method":"CRLF3 knockout iPSC lines differentiated to neurons; rotenone-induced apoptosis assay with EV-3 treatment; apoptotic gene expression profiling","journal":"Frontiers in molecular neuroscience","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — clean KO in human iPSC-derived neurons, defined phenotypic rescue experiment, identifies specific ligand (EV-3) and receptor relationship","pmids":["37168680"],"is_preprint":false},{"year":2023,"finding":"The CRLF3 L389P variant does not impair protein expression but causes impaired neuronal maturation and dendrite formation in human cerebral organoids and mouse brains; Crlf3L389P-mutant mouse hippocampal neurons have reduced dendrite lengths, branching, firing rates, and synaptic current amplitudes without axonal deficits.","method":"hiPSC lines and genetically engineered mice carrying L389P knock-in; cerebral organoid modeling; neuronal morphometry; electrophysiology of hippocampal neurons; Western blot for protein expression","journal":"Human molecular genetics","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — orthogonal methods (organoids, mouse model, electrophysiology, morphometry) in single lab, consistent finding across human and mouse models","pmids":["37712888"],"is_preprint":false},{"year":2022,"finding":"CRLF3-mediated neuroprotection in insects operates through prevention of hypoxia-induced upregulation of pro-apoptotic acetylcholinesterase (ace-1 and ace-2): activation of CRLF3 by erythropoietin prevented increased acetylcholinesterase expression under apoptogenic conditions, while high (toxic) Epo concentrations induced ace-1 expression and promoted apoptosis.","method":"RNAi knockdown of ace-1 and ace-2 in Tribolium primary brain neurons; pharmacological AChE inhibition; Epo treatment; cell survival and gene expression assays under hypoxia","journal":"Scientific reports","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — multiple orthogonal approaches (RNAi, pharmacology, gene expression) in single lab identifying downstream mechanism","pmids":["36329181"],"is_preprint":false},{"year":2025,"finding":"Locust CRLF3 can be activated by human thrombopoietin (neuroprotective), but not by human prolactin or growth hormone; additionally, erythropoietic/neuroprotective peptides HBSP, P16, and EMP1 also protect locust neurons via CRLF3, indicating a broader ligand spectrum than the classical Epo receptor. Downstream signaling involves JAK/STAT activity.","method":"Primary locust brain neuron cultures; hypoxia-induced apoptosis assays with specific cytokines and peptides; RNAi knockdown of CRLF3 to confirm receptor dependence; JAK/STAT pathway readouts","journal":"Journal of neurochemistry","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — functional assays with RNAi confirmation of receptor involvement, multiple ligands tested systematically, single lab","pmids":["40903881"],"is_preprint":false},{"year":2025,"finding":"CRLF3 physically interacts with ACTR2 (co-immunoprecipitation confirmed), and this interaction promotes hepatocellular carcinoma cell proliferation, migration, and immune escape; knockdown of CRLF3 inhibited HCC cell growth and tumor growth in vivo, and increased CD8+ T cell activity, effects that were rescued by ACTR2 overexpression.","method":"Co-immunoprecipitation and Western blot; MTT, colony formation, Transwell assays in HepG2 cells; flow cytometry for apoptosis and CD8+ T cell activation; nude mouse xenograft model","journal":"Cytotechnology","confidence":"Low","confidence_rationale":"Tier 3 / Weak — single lab, single co-IP for interaction, functional assays without orthogonal structural/mechanistic validation","pmids":["40469577"],"is_preprint":false}],"current_model":"CRLF3 is an evolutionarily conserved class I cytokine receptor that functions as a neuroprotective receptor activated by erythropoietin, its non-erythropoietic splice variant EV-3, thrombopoietin, and related peptides via JAK/STAT signaling to suppress pro-apoptotic acetylcholinesterase upregulation; in mammals it also regulates neuronal maturation and dendrite formation through RhoA signaling, controls the preplatelet-to-platelet fission step through interaction with Hippo pathway members affecting microtubule glutamylation, is required for early hematopoiesis, and interacts with ACTR2 to influence cancer cell behavior."},"narrative":{"mechanistic_narrative":"CRLF3 is an evolutionarily conserved cytokine receptor that mediates neuroprotection and regulates neuronal maturation and hematopoietic development [PMID:28769759, PMID:37168680, PMID:35051265]. In insect and human neurons it is required for the anti-apoptotic effect of erythropoietin (Epo) and its non-erythropoietic splice variant EV-3 against serum-deprivation-, hypoxia-, and rotenone-induced cell death, with receptor loss abolishing protection [PMID:28769759, PMID:31680856, PMID:37168680]. Its ligand spectrum is broader than the classical Epo receptor, encompassing thrombopoietin and the erythropoietic/neuroprotective peptides HBSP, P16, and EMP1 but not prolactin or growth hormone, and downstream signaling proceeds through JAK/STAT activity [PMID:40903881]. Neuroprotection is executed at least in part by preventing hypoxia-induced upregulation of pro-apoptotic acetylcholinesterase, with the protective response showing a biphasic dependence on ligand dose [PMID:36329181]. Beyond cytokine signaling, CRLF3 controls neuronal differentiation and maturation downstream of RhoA signaling, and a non-expression-impairing L389P variant compromises dendrite outgrowth, branching, and synaptic function in human organoids and mouse hippocampal neurons [PMID:34233200, PMID:37712888]. CRLF3 is also required for early hematopoiesis in zebrafish and regulates the preplatelet-to-platelet fission step in mice, where it interacts with Hippo pathway members and constrains microtubule glutamylation and stability [PMID:35795682, PMID:35051265]. A physical interaction with ACTR2 has been linked to hepatocellular carcinoma cell behavior [PMID:40469577].","teleology":[{"year":2017,"claim":"Established that CRLF3 is functionally required for erythropoietin-mediated neuroprotection, defining the protein as a participant in Epo anti-apoptotic signaling rather than a passive marker.","evidence":"RNAi knockdown in primary Tribolium castaneum brain neurons with recombinant human Epo and EV-3 in apoptosis assays","pmids":["28769759"],"confidence":"Medium","gaps":["Did not demonstrate direct ligand binding to CRLF3","Downstream signaling pathway not defined","Mammalian relevance untested in this study"]},{"year":2019,"claim":"Confirmed the neuroprotective requirement for CRLF3 in a second, hemimetabolous insect species, indicating evolutionary conservation of the Epo-CRLF3 axis.","evidence":"Soaking RNAi in primary Locusta migratoria brain neuron cultures with hypoxia-induced apoptosis assays and recombinant human Epo","pmids":["31680856"],"confidence":"Medium","gaps":["No identification of the endogenous insect ligand","No biochemical receptor-ligand interaction shown"]},{"year":2021,"claim":"Connected CRLF3 to an endogenous cytokine context by showing it is required for neuroprotection conferred by native hemolymph, moving beyond exogenous human Epo.","evidence":"RNAi knockdown of crlf3 in locust and Tribolium neurons with hemolymph serum survival assays","pmids":["33897456"],"confidence":"Medium","gaps":["The endogenous hemolymph ligand was not molecularly identified","Direct binding not demonstrated"]},{"year":2021,"claim":"Extended CRLF3 function into mammalian neurodevelopment, placing it as a regulator of neuronal maturation downstream of RhoA signaling.","evidence":"Loss-of-function in patient-derived hiPSC cerebral organoids with phenotypic rescue and pathway analysis","pmids":["34233200"],"confidence":"Medium","gaps":["Link between cytokine receptor activity and RhoA signaling unresolved","Single lab, organoid model"]},{"year":2022,"claim":"Identified a non-neuronal physiological role in megakaryocyte biology, showing CRLF3 controls the preplatelet-to-platelet fission step via microtubule regulation and Hippo pathway interaction.","evidence":"Crlf3 knockout mouse, platelet counts, EM, microtubule glutamylation/stability assays, co-IP with Hippo pathway members","pmids":["35051265"],"confidence":"Medium","gaps":["Direct biochemical partners within the Hippo pathway not fully resolved","Mechanism linking CRLF3 to glutamylation enzymes unknown","Single lab"]},{"year":2022,"claim":"Defined a developmental hematopoietic requirement for CRLF3, showing it is needed for primitive and early definitive hematopoiesis across lineages.","evidence":"CRISPR-generated crlf3 mutant zebrafish with in situ hybridization for progenitor markers","pmids":["35795682"],"confidence":"Medium","gaps":["Signaling pathway driving progenitor reduction not defined","Single model system"]},{"year":2022,"claim":"Resolved a downstream effector of CRLF3 neuroprotection by showing it acts by preventing hypoxia-induced upregulation of pro-apoptotic acetylcholinesterase, with biphasic ligand dose dependence.","evidence":"RNAi of ace-1/ace-2, pharmacological AChE inhibition, and Epo treatment in Tribolium neurons under hypoxia","pmids":["36329181"],"confidence":"Medium","gaps":["Intermediate signaling between CRLF3 and ace transcription not mapped","Conservation of AChE mechanism in mammals untested"]},{"year":2023,"claim":"Demonstrated that human CRLF3 functions as the receptor for the non-erythropoietic Epo variant EV-3 in neuroprotection, transferring the insect mechanism to human neurons.","evidence":"CRLF3 knockout human iPSC-derived neurons in rotenone apoptosis assays with EV-3 and apoptotic gene expression profiling","pmids":["37168680"],"confidence":"Medium","gaps":["Direct EV-3 binding to CRLF3 not biochemically shown","Receptor activation mechanism unresolved"]},{"year":2023,"claim":"Showed that a specific CRLF3 missense variant (L389P) selectively disrupts neuronal maturation and synaptic function without affecting protein expression, separating its developmental function from protein stability.","evidence":"L389P knock-in hiPSC organoids and mice, neuronal morphometry, hippocampal electrophysiology, Western blot","pmids":["37712888"],"confidence":"Medium","gaps":["Molecular consequence of L389P on receptor function undefined","Mechanistic link to dendrite/synapse machinery unknown"]},{"year":2025,"claim":"Defined CRLF3 as a promiscuous cytokine receptor activated by thrombopoietin and multiple erythropoietic/neuroprotective peptides via JAK/STAT signaling, distinguishing it from the classical Epo receptor.","evidence":"Locust neuron apoptosis assays with specific cytokines/peptides, RNAi confirmation, and JAK/STAT readouts","pmids":["40903881"],"confidence":"Medium","gaps":["Direct binding affinities for the various ligands not measured","Structural basis of broad ligand recognition unknown"]},{"year":2025,"claim":"Implicated CRLF3 in cancer through a physical interaction with ACTR2 driving hepatocellular carcinoma proliferation, migration, and immune escape.","evidence":"Co-immunoprecipitation, proliferation/migration assays in HepG2, CD8+ T cell assays, and nude mouse xenografts with ACTR2 rescue","pmids":["40469577"],"confidence":"Low","gaps":["Single co-IP without reciprocal/structural validation","Mechanism connecting CRLF3-ACTR2 to proliferation undefined","Relationship to cytokine receptor function unclear"]},{"year":null,"claim":"Direct biochemical demonstration of ligand binding to CRLF3 and the structural/signaling mechanism converting receptor engagement into the divergent RhoA, Hippo/microtubule, and JAK/STAT outputs remains unresolved.","evidence":"","pmids":[],"confidence":"Medium","gaps":["No direct receptor-ligand binding assay reported","No structural model of the receptor","How one receptor drives neuroprotection, dendritogenesis, hematopoiesis, and platelet fission is unexplained"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0060089","term_label":"molecular transducer activity","supporting_discovery_ids":[1,6,9]},{"term_id":"GO:0048018","term_label":"receptor ligand activity","supporting_discovery_ids":[9]}],"localization":[],"pathway":[{"term_id":"R-HSA-162582","term_label":"Signal Transduction","supporting_discovery_ids":[9,0]},{"term_id":"R-HSA-5357801","term_label":"Programmed Cell Death","supporting_discovery_ids":[1,6,8]},{"term_id":"R-HSA-109582","term_label":"Hemostasis","supporting_discovery_ids":[4]}],"complexes":[],"partners":["ACTR2"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"Q8IUI8","full_name":"Cytokine receptor-like factor 3","aliases":["Cytokine receptor-like molecule 9","CREME-9","Cytokine receptor-related protein 4","Type I cytokine receptor-like factor p48"],"length_aa":442,"mass_kda":49.8,"function":"May play a role in the negative regulation of cell cycle progression","subcellular_location":"Cytoplasm","url":"https://www.uniprot.org/uniprotkb/Q8IUI8/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/CRLF3","classification":"Not Classified","n_dependent_lines":12,"n_total_lines":1208,"dependency_fraction":0.009933774834437087},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[],"url":"https://opencell.sf.czbiohub.org/search/CRLF3","total_profiled":1310},"omim":[{"mim_id":"614853","title":"CYTOKINE RECEPTOR-LIKE FACTOR 3; CRLF3","url":"https://www.omim.org/entry/614853"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Approved","locations":[{"location":"Plasma membrane","reliability":"Approved"},{"location":"Cytosol","reliability":"Approved"}],"tissue_specificity":"Tissue enhanced","tissue_distribution":"Detected in all","driving_tissues":[{"tissue":"lymphoid tissue","ntpm":33.2}],"url":"https://www.proteinatlas.org/search/CRLF3"},"hgnc":{"alias_symbol":["CREME9","CYTOR4"],"prev_symbol":[]},"alphafold":{"accession":"Q8IUI8","domains":[{"cath_id":"2.60.40.10","chopping":"182-269","consensus_level":"high","plddt":91.8267,"start":182,"end":269},{"cath_id":"2.60.120.920","chopping":"283-390_397-440","consensus_level":"high","plddt":91.5103,"start":283,"end":440},{"cath_id":"1.20.5","chopping":"22-140","consensus_level":"medium","plddt":91.1956,"start":22,"end":140}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q8IUI8","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q8IUI8-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q8IUI8-F1-predicted_aligned_error_v6.png","plddt_mean":89.69},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=CRLF3","jax_strain_url":"https://www.jax.org/strain/search?query=CRLF3"},"sequence":{"accession":"Q8IUI8","fasta_url":"https://rest.uniprot.org/uniprotkb/Q8IUI8.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q8IUI8/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q8IUI8"}},"corpus_meta":[{"pmid":"34233200","id":"PMC_34233200","title":"Patient-derived iPSC-cerebral organoid modeling of the 17q11.2 microdeletion syndrome establishes CRLF3 as a critical regulator of neurogenesis.","date":"2021","source":"Cell reports","url":"https://pubmed.ncbi.nlm.nih.gov/34233200","citation_count":42,"is_preprint":false},{"pmid":"28769759","id":"PMC_28769759","title":"The Insect Ortholog of the Human Orphan Cytokine Receptor CRLF3 Is a Neuroprotective Erythropoietin Receptor.","date":"2017","source":"Frontiers in molecular neuroscience","url":"https://pubmed.ncbi.nlm.nih.gov/28769759","citation_count":26,"is_preprint":false},{"pmid":"31680856","id":"PMC_31680856","title":"The Orphan Cytokine Receptor CRLF3 Emerged With the Origin of the Nervous System and Is a Neuroprotective Erythropoietin Receptor in Locusts.","date":"2019","source":"Frontiers in molecular neuroscience","url":"https://pubmed.ncbi.nlm.nih.gov/31680856","citation_count":21,"is_preprint":false},{"pmid":"35051265","id":"PMC_35051265","title":"CRLF3 plays a key role in the final stage of platelet genesis and is a potential therapeutic target for thrombocythemia.","date":"2022","source":"Blood","url":"https://pubmed.ncbi.nlm.nih.gov/35051265","citation_count":19,"is_preprint":false},{"pmid":"32830257","id":"PMC_32830257","title":"A Genome-wide Association Study Identifies SERPINB10, CRLF3, STX7, LAMP3, IFNG-AS1, and KRT80 As Risk Loci Contributing to Cutaneous Leishmaniasis in Brazil.","date":"2021","source":"Clinical infectious diseases : an official publication of the Infectious Diseases Society of America","url":"https://pubmed.ncbi.nlm.nih.gov/32830257","citation_count":19,"is_preprint":false},{"pmid":"37168680","id":"PMC_37168680","title":"The cytokine receptor CRLF3 is a human neuroprotective EV-3 (Epo) receptor.","date":"2023","source":"Frontiers in molecular neuroscience","url":"https://pubmed.ncbi.nlm.nih.gov/37168680","citation_count":8,"is_preprint":false},{"pmid":"33897456","id":"PMC_33897456","title":"Locust Hemolymph Conveys Erythropoietin-Like Cytoprotection via Activation of the Cytokine Receptor CRLF3.","date":"2021","source":"Frontiers in physiology","url":"https://pubmed.ncbi.nlm.nih.gov/33897456","citation_count":8,"is_preprint":false},{"pmid":"35795682","id":"PMC_35795682","title":"Cytokine Receptor-Like Factor 3 (CRLF3) Contributes to Early Zebrafish Hematopoiesis.","date":"2022","source":"Frontiers in immunology","url":"https://pubmed.ncbi.nlm.nih.gov/35795682","citation_count":7,"is_preprint":false},{"pmid":"37712888","id":"PMC_37712888","title":"A common single nucleotide variant in the cytokine receptor-like factor-3 (CRLF3) gene causes neuronal deficits in human and mouse cells.","date":"2023","source":"Human molecular genetics","url":"https://pubmed.ncbi.nlm.nih.gov/37712888","citation_count":6,"is_preprint":false},{"pmid":"36329181","id":"PMC_36329181","title":"Protection of insect neurons by erythropoietin/CRLF3-mediated regulation of pro-apoptotic acetylcholinesterase.","date":"2022","source":"Scientific reports","url":"https://pubmed.ncbi.nlm.nih.gov/36329181","citation_count":4,"is_preprint":false},{"pmid":"40331935","id":"PMC_40331935","title":"Cytokine Receptor-like Factor 3 (CRLF3) and Its Emerging Roles in Neurobiology, Hematopoiesis and Related Human Diseases.","date":"2025","source":"International journal of molecular sciences","url":"https://pubmed.ncbi.nlm.nih.gov/40331935","citation_count":3,"is_preprint":false},{"pmid":"40903881","id":"PMC_40903881","title":"Multiple Mammalian Cytokines and Erythropoietin-Mimetic Peptides Protect Insect Neurons via Phylogenetically Conserved Cytokine Receptor-Like Factor 3 (CRLF3).","date":"2025","source":"Journal of neurochemistry","url":"https://pubmed.ncbi.nlm.nih.gov/40903881","citation_count":1,"is_preprint":false},{"pmid":"40469577","id":"PMC_40469577","title":"Mechanisms of CRLF3-targeted binding to ACTR2 to promote hepatocellular carcinoma progression and effects on the immune microenvironment.","date":"2025","source":"Cytotechnology","url":"https://pubmed.ncbi.nlm.nih.gov/40469577","citation_count":0,"is_preprint":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":9465,"output_tokens":2942,"usd":0.036263,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":10241,"output_tokens":3528,"usd":0.069703,"stage2_stop_reason":"end_turn"},"total_usd":0.105966,"stage1_batch_id":"msgbatch_01ACAxJQabDsht39JXeWG22d","stage2_batch_id":"msgbatch_01QEU22A9U5sbPTgsMzTmvSf","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2021,\n      \"finding\": \"CRLF3 loss-of-function in patient-derived hiPSC-forebrain cerebral organoids causes neuronal differentiation, survival, and maturation defects through impaired RhoA signaling, identifying CRLF3 as a regulator of neuronal maturation downstream of RhoA.\",\n      \"method\": \"hiPSC-derived cerebral organoids from NF1-TGD patients with reduced CRLF3 expression; phenotypic rescue experiments; pathway analysis\",\n      \"journal\": \"Cell reports\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — loss-of-function in patient-derived organoids with defined cellular phenotype and pathway placement (RhoA signaling), single lab with multiple readouts\",\n      \"pmids\": [\"34233200\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"Insect (Tribolium castaneum) ortholog of CRLF3 is required for erythropoietin (Epo)-mediated neuroprotection: RNAi knockdown of CRLF3 abolished the ability of recombinant human Epo and non-erythropoietic splice variant EV-3 to prevent serum-deprivation- and hypoxia-induced apoptosis in primary neuronal cultures.\",\n      \"method\": \"In vitro RNAi knockdown in primary Tribolium brain neuron cultures; apoptosis assay with recombinant human Epo and EV-3 treatment\",\n      \"journal\": \"Frontiers in molecular neuroscience\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Strong — replicated across two insect species (Tribolium and Locusta) by independent studies, consistent RNAi loss-of-function with defined neuroprotective phenotype\",\n      \"pmids\": [\"28769759\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"CRLF3 ortholog in Locusta migratoria mediates erythropoietin-induced neuroprotection: soaking RNAi knockdown of Lm-crlf3 abolished the protective effect of recombinant human Epo against hypoxia-induced apoptosis in primary locust brain neuron cultures.\",\n      \"method\": \"Soaking RNAi in primary Locusta migratoria brain cell cultures; hypoxia-induced apoptosis assay with recombinant human Epo\",\n      \"journal\": \"Frontiers in molecular neuroscience\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Strong — replicates the Tribolium finding in a second insect species (hemimetabolous), consistent loss-of-function phenotype\",\n      \"pmids\": [\"31680856\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"CRLF3 mediates neuroprotection by an endogenous conserved cytokine present in locust hemolymph: RNAi knockdown of crlf3 in both Locusta migratoria and Tribolium castaneum neurons abolished the neuroprotective effect of locust hemolymph serum against hypoxia-induced apoptosis.\",\n      \"method\": \"RNAi knockdown of crlf3 in primary locust and Tribolium neuron/hemocyte cultures; cell survival assay with locust hemolymph serum supplementation\",\n      \"journal\": \"Frontiers in physiology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — loss-of-function in two species with consistent phenotype, single lab, identifies endogenous ligand context\",\n      \"pmids\": [\"33897456\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"CRLF3 deficiency in mice leads to a 25–48% reduction in platelet count without affecting other blood cell lineages, and Crlf3−/− preplatelets show increased microtubule stability associated with increased microtubule glutamylation via CRLF3 interaction with key members of the Hippo pathway, identifying CRLF3 as a regulator of the preplatelet-to-platelet maturation (fission) step.\",\n      \"method\": \"Crlf3 knockout mouse model; platelet counting; electron microscopy of preplatelets; microtubule stability assays; co-immunoprecipitation with Hippo pathway members; JAK2 V617F essential thrombocythemia mouse model cross\",\n      \"journal\": \"Blood\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — clean KO mouse with lineage-specific phenotype and mechanistic interaction (Hippo pathway co-IP), single lab\",\n      \"pmids\": [\"35051265\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"CRLF3 is required for early hematopoiesis in zebrafish: crlf3 mutants generated by genome editing show significant reduction in primitive hematopoiesis and early definitive hematopoiesis, affecting multiple lineages via decreased early progenitors.\",\n      \"method\": \"CRISPR/genome editing to generate crlf3 mutant zebrafish; in situ hybridization and cell lineage markers for hematopoietic progenitors\",\n      \"journal\": \"Frontiers in immunology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Weak — clean genetic KO in zebrafish with defined hematopoietic phenotype, single lab, single model system\",\n      \"pmids\": [\"35795682\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"Human CRLF3 functions as a receptor for the non-erythropoietic Epo splice variant EV-3 mediating neuroprotection: CRLF3 knockout iPSC-derived neurons failed to be protected by EV-3 against rotenone-induced apoptosis, and this was associated with differential expression of pro- and anti-apoptotic genes.\",\n      \"method\": \"CRLF3 knockout iPSC lines differentiated to neurons; rotenone-induced apoptosis assay with EV-3 treatment; apoptotic gene expression profiling\",\n      \"journal\": \"Frontiers in molecular neuroscience\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — clean KO in human iPSC-derived neurons, defined phenotypic rescue experiment, identifies specific ligand (EV-3) and receptor relationship\",\n      \"pmids\": [\"37168680\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"The CRLF3 L389P variant does not impair protein expression but causes impaired neuronal maturation and dendrite formation in human cerebral organoids and mouse brains; Crlf3L389P-mutant mouse hippocampal neurons have reduced dendrite lengths, branching, firing rates, and synaptic current amplitudes without axonal deficits.\",\n      \"method\": \"hiPSC lines and genetically engineered mice carrying L389P knock-in; cerebral organoid modeling; neuronal morphometry; electrophysiology of hippocampal neurons; Western blot for protein expression\",\n      \"journal\": \"Human molecular genetics\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — orthogonal methods (organoids, mouse model, electrophysiology, morphometry) in single lab, consistent finding across human and mouse models\",\n      \"pmids\": [\"37712888\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"CRLF3-mediated neuroprotection in insects operates through prevention of hypoxia-induced upregulation of pro-apoptotic acetylcholinesterase (ace-1 and ace-2): activation of CRLF3 by erythropoietin prevented increased acetylcholinesterase expression under apoptogenic conditions, while high (toxic) Epo concentrations induced ace-1 expression and promoted apoptosis.\",\n      \"method\": \"RNAi knockdown of ace-1 and ace-2 in Tribolium primary brain neurons; pharmacological AChE inhibition; Epo treatment; cell survival and gene expression assays under hypoxia\",\n      \"journal\": \"Scientific reports\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — multiple orthogonal approaches (RNAi, pharmacology, gene expression) in single lab identifying downstream mechanism\",\n      \"pmids\": [\"36329181\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"Locust CRLF3 can be activated by human thrombopoietin (neuroprotective), but not by human prolactin or growth hormone; additionally, erythropoietic/neuroprotective peptides HBSP, P16, and EMP1 also protect locust neurons via CRLF3, indicating a broader ligand spectrum than the classical Epo receptor. Downstream signaling involves JAK/STAT activity.\",\n      \"method\": \"Primary locust brain neuron cultures; hypoxia-induced apoptosis assays with specific cytokines and peptides; RNAi knockdown of CRLF3 to confirm receptor dependence; JAK/STAT pathway readouts\",\n      \"journal\": \"Journal of neurochemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — functional assays with RNAi confirmation of receptor involvement, multiple ligands tested systematically, single lab\",\n      \"pmids\": [\"40903881\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"CRLF3 physically interacts with ACTR2 (co-immunoprecipitation confirmed), and this interaction promotes hepatocellular carcinoma cell proliferation, migration, and immune escape; knockdown of CRLF3 inhibited HCC cell growth and tumor growth in vivo, and increased CD8+ T cell activity, effects that were rescued by ACTR2 overexpression.\",\n      \"method\": \"Co-immunoprecipitation and Western blot; MTT, colony formation, Transwell assays in HepG2 cells; flow cytometry for apoptosis and CD8+ T cell activation; nude mouse xenograft model\",\n      \"journal\": \"Cytotechnology\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — single lab, single co-IP for interaction, functional assays without orthogonal structural/mechanistic validation\",\n      \"pmids\": [\"40469577\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"CRLF3 is an evolutionarily conserved class I cytokine receptor that functions as a neuroprotective receptor activated by erythropoietin, its non-erythropoietic splice variant EV-3, thrombopoietin, and related peptides via JAK/STAT signaling to suppress pro-apoptotic acetylcholinesterase upregulation; in mammals it also regulates neuronal maturation and dendrite formation through RhoA signaling, controls the preplatelet-to-platelet fission step through interaction with Hippo pathway members affecting microtubule glutamylation, is required for early hematopoiesis, and interacts with ACTR2 to influence cancer cell behavior.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"CRLF3 is an evolutionarily conserved cytokine receptor that mediates neuroprotection and regulates neuronal maturation and hematopoietic development [#1, #6, #4]. In insect and human neurons it is required for the anti-apoptotic effect of erythropoietin (Epo) and its non-erythropoietic splice variant EV-3 against serum-deprivation-, hypoxia-, and rotenone-induced cell death, with receptor loss abolishing protection [#1, #2, #6]. Its ligand spectrum is broader than the classical Epo receptor, encompassing thrombopoietin and the erythropoietic/neuroprotective peptides HBSP, P16, and EMP1 but not prolactin or growth hormone, and downstream signaling proceeds through JAK/STAT activity [#9]. Neuroprotection is executed at least in part by preventing hypoxia-induced upregulation of pro-apoptotic acetylcholinesterase, with the protective response showing a biphasic dependence on ligand dose [#8]. Beyond cytokine signaling, CRLF3 controls neuronal differentiation and maturation downstream of RhoA signaling, and a non-expression-impairing L389P variant compromises dendrite outgrowth, branching, and synaptic function in human organoids and mouse hippocampal neurons [#0, #7]. CRLF3 is also required for early hematopoiesis in zebrafish and regulates the preplatelet-to-platelet fission step in mice, where it interacts with Hippo pathway members and constrains microtubule glutamylation and stability [#5, #4]. A physical interaction with ACTR2 has been linked to hepatocellular carcinoma cell behavior [#10].\",\n  \"teleology\": [\n    {\n      \"year\": 2017,\n      \"claim\": \"Established that CRLF3 is functionally required for erythropoietin-mediated neuroprotection, defining the protein as a participant in Epo anti-apoptotic signaling rather than a passive marker.\",\n      \"evidence\": \"RNAi knockdown in primary Tribolium castaneum brain neurons with recombinant human Epo and EV-3 in apoptosis assays\",\n      \"pmids\": [\"28769759\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Did not demonstrate direct ligand binding to CRLF3\", \"Downstream signaling pathway not defined\", \"Mammalian relevance untested in this study\"]\n    },\n    {\n      \"year\": 2019,\n      \"claim\": \"Confirmed the neuroprotective requirement for CRLF3 in a second, hemimetabolous insect species, indicating evolutionary conservation of the Epo-CRLF3 axis.\",\n      \"evidence\": \"Soaking RNAi in primary Locusta migratoria brain neuron cultures with hypoxia-induced apoptosis assays and recombinant human Epo\",\n      \"pmids\": [\"31680856\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No identification of the endogenous insect ligand\", \"No biochemical receptor-ligand interaction shown\"]\n    },\n    {\n      \"year\": 2021,\n      \"claim\": \"Connected CRLF3 to an endogenous cytokine context by showing it is required for neuroprotection conferred by native hemolymph, moving beyond exogenous human Epo.\",\n      \"evidence\": \"RNAi knockdown of crlf3 in locust and Tribolium neurons with hemolymph serum survival assays\",\n      \"pmids\": [\"33897456\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"The endogenous hemolymph ligand was not molecularly identified\", \"Direct binding not demonstrated\"]\n    },\n    {\n      \"year\": 2021,\n      \"claim\": \"Extended CRLF3 function into mammalian neurodevelopment, placing it as a regulator of neuronal maturation downstream of RhoA signaling.\",\n      \"evidence\": \"Loss-of-function in patient-derived hiPSC cerebral organoids with phenotypic rescue and pathway analysis\",\n      \"pmids\": [\"34233200\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Link between cytokine receptor activity and RhoA signaling unresolved\", \"Single lab, organoid model\"]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"Identified a non-neuronal physiological role in megakaryocyte biology, showing CRLF3 controls the preplatelet-to-platelet fission step via microtubule regulation and Hippo pathway interaction.\",\n      \"evidence\": \"Crlf3 knockout mouse, platelet counts, EM, microtubule glutamylation/stability assays, co-IP with Hippo pathway members\",\n      \"pmids\": [\"35051265\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct biochemical partners within the Hippo pathway not fully resolved\", \"Mechanism linking CRLF3 to glutamylation enzymes unknown\", \"Single lab\"]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"Defined a developmental hematopoietic requirement for CRLF3, showing it is needed for primitive and early definitive hematopoiesis across lineages.\",\n      \"evidence\": \"CRISPR-generated crlf3 mutant zebrafish with in situ hybridization for progenitor markers\",\n      \"pmids\": [\"35795682\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Signaling pathway driving progenitor reduction not defined\", \"Single model system\"]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"Resolved a downstream effector of CRLF3 neuroprotection by showing it acts by preventing hypoxia-induced upregulation of pro-apoptotic acetylcholinesterase, with biphasic ligand dose dependence.\",\n      \"evidence\": \"RNAi of ace-1/ace-2, pharmacological AChE inhibition, and Epo treatment in Tribolium neurons under hypoxia\",\n      \"pmids\": [\"36329181\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Intermediate signaling between CRLF3 and ace transcription not mapped\", \"Conservation of AChE mechanism in mammals untested\"]\n    },\n    {\n      \"year\": 2023,\n      \"claim\": \"Demonstrated that human CRLF3 functions as the receptor for the non-erythropoietic Epo variant EV-3 in neuroprotection, transferring the insect mechanism to human neurons.\",\n      \"evidence\": \"CRLF3 knockout human iPSC-derived neurons in rotenone apoptosis assays with EV-3 and apoptotic gene expression profiling\",\n      \"pmids\": [\"37168680\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct EV-3 binding to CRLF3 not biochemically shown\", \"Receptor activation mechanism unresolved\"]\n    },\n    {\n      \"year\": 2023,\n      \"claim\": \"Showed that a specific CRLF3 missense variant (L389P) selectively disrupts neuronal maturation and synaptic function without affecting protein expression, separating its developmental function from protein stability.\",\n      \"evidence\": \"L389P knock-in hiPSC organoids and mice, neuronal morphometry, hippocampal electrophysiology, Western blot\",\n      \"pmids\": [\"37712888\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Molecular consequence of L389P on receptor function undefined\", \"Mechanistic link to dendrite/synapse machinery unknown\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Defined CRLF3 as a promiscuous cytokine receptor activated by thrombopoietin and multiple erythropoietic/neuroprotective peptides via JAK/STAT signaling, distinguishing it from the classical Epo receptor.\",\n      \"evidence\": \"Locust neuron apoptosis assays with specific cytokines/peptides, RNAi confirmation, and JAK/STAT readouts\",\n      \"pmids\": [\"40903881\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct binding affinities for the various ligands not measured\", \"Structural basis of broad ligand recognition unknown\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Implicated CRLF3 in cancer through a physical interaction with ACTR2 driving hepatocellular carcinoma proliferation, migration, and immune escape.\",\n      \"evidence\": \"Co-immunoprecipitation, proliferation/migration assays in HepG2, CD8+ T cell assays, and nude mouse xenografts with ACTR2 rescue\",\n      \"pmids\": [\"40469577\"],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"Single co-IP without reciprocal/structural validation\", \"Mechanism connecting CRLF3-ACTR2 to proliferation undefined\", \"Relationship to cytokine receptor function unclear\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"Direct biochemical demonstration of ligand binding to CRLF3 and the structural/signaling mechanism converting receptor engagement into the divergent RhoA, Hippo/microtubule, and JAK/STAT outputs remains unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No direct receptor-ligand binding assay reported\", \"No structural model of the receptor\", \"How one receptor drives neuroprotection, dendritogenesis, hematopoiesis, and platelet fission is unexplained\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0060089\", \"supporting_discovery_ids\": [1, 6, 9]},\n      {\"term_id\": \"GO:0048018\", \"supporting_discovery_ids\": [9]}\n    ],\n    \"localization\": [],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-162582\", \"supporting_discovery_ids\": [9, 0]},\n      {\"term_id\": \"R-HSA-5357801\", \"supporting_discovery_ids\": [1, 6, 8]},\n      {\"term_id\": \"R-HSA-109582\", \"supporting_discovery_ids\": [4]}\n    ],\n    \"complexes\": [],\n    \"partners\": [\"ACTR2\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":7,"faith_total":7,"faith_pct":100.0}}