{"gene":"C8ORF33","run_date":"2026-04-28T17:12:38","timeline":{"discoveries":[{"year":2025,"finding":"C8orf33 is a nuclear protein that localizes predominantly to the nucleolus and is recruited to DNA double-strand break (DSB) sites in both nuclear and nucleolar regions. C8orf33 promotes recruitment of 53BP1 to DSB sites, thereby channeling DSB repair toward non-homologous end joining (NHEJ). Mechanistically, C8orf33 antagonizes chromatin association of the KAT8 acetyltransferase at DSB sites, leading to reduced histone H4 lysine 16 acetylation (H4K16ac) levels. Loss of C8orf33 enhances KAT8 chromatin binding, increases H4K16ac, promotes recruitment of HR factors BRCA1 and RAD51, and suppresses 53BP1 accumulation, thereby shifting DSB repair pathway choice from NHEJ toward homologous recombination (HR). C8orf33 deficiency causes accelerated loss of ribosomal DNA repeats and increased cell death, demonstrating its role in safeguarding genomic integrity.","method":"Chromatin profiling, immunofluorescence microscopy of DSB recruitment, loss-of-function (siRNA/KO) with readouts of 53BP1/BRCA1/RAD51 foci, H4K16ac ChIP, DNA end resection assays, rDNA repeat stability assay","journal":"Cell death & disease","confidence":"High","confidence_rationale":"Tier 2 — multiple orthogonal methods (chromatin profiling, foci assays, ChIP, functional genomic readouts) in a single study with rigorous mechanistic pathway placement","pmids":["41249114"],"is_preprint":false},{"year":2026,"finding":"C8orf33 knockdown in HCC cell lines reduces proliferation, migration, and tumorigenic capacity, and increases apoptosis. C8orf33 loss is accompanied by reduced mRNA and protein levels of MIF and its receptor components (CD74, CXCR4, CD44), and in xenografts reduces infiltration of CD163/CD206-positive M2-like macrophages, suggesting C8orf33 contributes to a tumor-promoting MIF signaling axis linked to immunomodulatory macrophage recruitment.","method":"siRNA knockdown in HCC cell lines, in vitro proliferation/migration/apoptosis assays, subcutaneous xenograft models, scRNA-seq, spatial transcriptomics, cell-cell communication analysis, qRT-PCR and western blot for MIF-axis components, IHC for macrophage markers","journal":"Discover oncology","confidence":"Medium","confidence_rationale":"Tier 2/3 — loss-of-function with defined phenotypic readout and partial pathway placement (MIF axis), single lab, correlative mechanistic link","pmids":["41965457"],"is_preprint":false}],"current_model":"C8orf33 is a nucleolar protein recruited to DNA double-strand break sites where it promotes NHEJ over HR by antagonizing KAT8-mediated H4K16 acetylation and facilitating 53BP1 recruitment while suppressing BRCA1/RAD51 accumulation; additionally, C8orf33 supports HCC cell survival and proliferation through a potential link to MIF-mediated macrophage immunomodulatory signaling."},"narrative":{"teleology":[{"year":2025,"claim":"The molecular function of C8orf33 was unknown; chromatin profiling and DSB recruitment assays established that it localizes to the nucleolus, is recruited to DSB sites, and channels repair toward NHEJ by antagonizing KAT8-dependent H4K16 acetylation and promoting 53BP1 recruitment, thereby safeguarding rDNA repeat stability.","evidence":"siRNA/KO in human cells with 53BP1/BRCA1/RAD51 foci quantification, H4K16ac ChIP, DNA end resection assays, and rDNA repeat stability assays","pmids":["41249114"],"confidence":"High","gaps":["Direct physical interaction between C8orf33 and KAT8 has not been demonstrated","Structural basis by which C8orf33 antagonizes KAT8 chromatin association is unknown","Whether C8orf33 plays additional roles in nucleolar functions beyond rDNA protection is unresolved"]},{"year":2026,"claim":"A role for C8orf33 in tumor cell biology was undefined; knockdown experiments in HCC cells revealed that C8orf33 supports proliferation, migration, and survival and sustains MIF-pathway signaling linked to immunomodulatory macrophage recruitment.","evidence":"siRNA knockdown in HCC cell lines with proliferation/apoptosis assays, subcutaneous xenograft models, scRNA-seq and spatial transcriptomics, qRT-PCR/western blot for MIF-axis components, IHC for macrophage markers","pmids":["41965457"],"confidence":"Medium","gaps":["Mechanistic link between C8orf33 and MIF transcription/signaling is correlative and not directly tested","Whether the pro-tumorigenic phenotype reflects C8orf33's DSB repair function or an independent pathway is unclear","Single-laboratory study; independent validation in additional tumor models is lacking"]},{"year":null,"claim":"Whether C8orf33 directly binds KAT8 or chromatin, its structural mechanism, and the relationship between its DSB repair and tumor-promoting functions remain unresolved.","evidence":"","pmids":[],"confidence":"Low","gaps":["No structural or biophysical characterization of C8orf33 exists","No direct binding partner has been biochemically validated","The contribution of NHEJ-promoting activity to rDNA maintenance versus general genome integrity is unresolved"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0098772","term_label":"molecular function regulator activity","supporting_discovery_ids":[0]}],"localization":[{"term_id":"GO:0005730","term_label":"nucleolus","supporting_discovery_ids":[0]},{"term_id":"GO:0005634","term_label":"nucleus","supporting_discovery_ids":[0]}],"pathway":[{"term_id":"R-HSA-73894","term_label":"DNA Repair","supporting_discovery_ids":[0]}],"complexes":[],"partners":["KAT8","TP53BP1"],"other_free_text":[]},"mechanistic_narrative":"C8orf33 is a nucleolar protein recruited to DNA double-strand break (DSB) sites, where it promotes non-homologous end joining (NHEJ) by facilitating 53BP1 accumulation and antagonizing KAT8 acetyltransferase chromatin association, thereby reducing H4K16 acetylation and suppressing BRCA1/RAD51-mediated homologous recombination [PMID:41249114]. C8orf33 deficiency leads to accelerated loss of ribosomal DNA repeats and increased cell death, indicating a role in safeguarding rDNA integrity [PMID:41249114]. In hepatocellular carcinoma cells, C8orf33 knockdown reduces proliferation and tumorigenic capacity and downregulates the MIF signaling axis (MIF, CD74, CXCR4, CD44), correlating with decreased M2-like macrophage infiltration in xenograft models [PMID:41965457]."},"prefetch_data":{"uniprot":{"accession":"Q9H7E9","full_name":"UPF0488 protein C8orf33","aliases":[],"length_aa":229,"mass_kda":25.0,"function":"","subcellular_location":"","url":"https://www.uniprot.org/uniprotkb/Q9H7E9/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/C8ORF33"},"opencell":{"profiled":true,"resolved_as":"","ensg_id":"ENSG00000182307","cell_line_id":"CID000391","localizations":[{"compartment":"cytoplasmic","grade":3},{"compartment":"nucleolus_gc","grade":3},{"compartment":"nucleoplasm","grade":2}],"interactors":[{"gene":"CHMP7","stoichiometry":0.2},{"gene":"NPM1","stoichiometry":0.2}],"url":"https://opencell.sf.czbiohub.org/target/CID000391","total_profiled":1310},"omim":[],"hpa":{"profiled":true,"resolved_as":"","reliability":"Uncertain","locations":[{"location":"Nucleoplasm","reliability":"Uncertain"},{"location":"Plasma membrane","reliability":"Uncertain"}],"tissue_specificity":"Low tissue specificity","tissue_distribution":"Detected in all","driving_tissues":[],"url":"https://www.proteinatlas.org/search/C8ORF33"},"hgnc":{"alias_symbol":["FLJ20989"],"prev_symbol":[]},"alphafold":{"accession":"Q9H7E9","domains":[{"cath_id":"-","chopping":"105-188","consensus_level":"high","plddt":95.0761,"start":105,"end":188}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q9H7E9","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q9H7E9-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q9H7E9-F1-predicted_aligned_error_v6.png","plddt_mean":71.19},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=C8ORF33","jax_strain_url":"https://www.jax.org/strain/search?query=C8ORF33"},"sequence":{"accession":"Q9H7E9","fasta_url":"https://rest.uniprot.org/uniprotkb/Q9H7E9.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q9H7E9/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q9H7E9"}},"corpus_meta":[{"pmid":"35091678","id":"PMC_35091678","title":"An mRNA expression-based signature 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promotes NHEJ by facilitating 53BP1 recruitment, inhibiting DNA end resection, and counteracting BRCA1 and RAD51 recruitment to DSB sites.\",\n      \"method\": \"Loss-of-function experiments, live imaging/fractionation for localization, chromatin immunoprecipitation, recruitment assays at DSB sites\",\n      \"journal\": \"Cell death & disease\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — reciprocal functional assays with multiple orthogonal methods (localization, recruitment assays, end-resection assays, factor recruitment) in a single rigorous study\",\n      \"pmids\": [\"41249114\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"C8orf33 antagonizes the chromatin association of KAT8 acetyltransferase at DSB sites, leading to reduced H4K16 acetylation (H4K16ac); loss of C8orf33 enhances KAT8 chromatin binding, increases H4K16ac, and thereby shifts DSB repair pathway choice from NHEJ toward homologous recombination.\",\n      \"method\": \"Chromatin profiling (ChIP), H4K16ac level measurement, KAT8 chromatin association assays in C8orf33-deficient cells\",\n      \"journal\": \"Cell death & disease\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1–2 — mechanistic chromatin profiling with epistatic pathway placement and multiple readouts in one rigorous study\",\n      \"pmids\": [\"41249114\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"Loss of C8orf33 causes genomic instability manifested as accelerated loss of ribosomal DNA repeats and increased cell death, attributable to elevated and inappropriate homologous recombination activity.\",\n      \"method\": \"rDNA repeat loss assay, cell death quantification in C8orf33-deficient cells\",\n      \"journal\": \"Cell death & disease\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — clean KO/KD with specific phenotypic readout; single lab\",\n      \"pmids\": [\"41249114\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2026,\n      \"finding\": \"C8orf33 knockdown in HCC cell lines reduces proliferation and migration, impairs tumorigenic capacity in xenografts, and increases apoptosis; knockdown is accompanied by reduced mRNA and protein levels of MIF and its receptor components (CD74, CXCR4, CD44), suggesting C8orf33 modulates MIF-axis signaling.\",\n      \"method\": \"siRNA/shRNA knockdown, in vitro proliferation and migration assays, subcutaneous xenograft models, RT-qPCR, western blot\",\n      \"journal\": \"Discover oncology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2–3 — loss-of-function with multiple cellular phenotypic readouts and molecular pathway link; single lab\",\n      \"pmids\": [\"41965457\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"C8orf33 is a nucleolar nuclear protein that is recruited to DNA double-strand break sites and regulates DSB repair pathway choice by antagonizing KAT8 acetyltransferase chromatin binding, thereby suppressing H4K16 acetylation, promoting 53BP1 recruitment, and channeling repair toward NHEJ over homologous recombination to maintain genomic integrity; separately, C8orf33 supports HCC cell proliferation, migration, and tumorigenic capacity at least partly through modulation of MIF-axis signaling.\"\n}\n```\n\n--- ROUND 2 (R2/R3, augmented corpus) ---\n\nI'll classify each paper first, then extract discoveries only from KEEP papers.\n\n**Classification:**\n\nRetrieved papers:\n1. PMID:35091678 — C8ORF33 mentioned only as part of a 6-gene expression signature; no mechanistic data on C8ORF33 itself. EXCLUDE (expression/biomarker only).\n2. PMID:29123978 — C8orf33 mentioned only in survival analysis context. EXCLUDE (expression/biomarker only).\n3. PMID:37672187 — Uses C8ORF33 as part of ORS signature; no mechanistic data on C8ORF33. EXCLUDE (expression/biomarker only).\n4. PMID:18479593 — No mention of C8ORF33 in abstract. EXCLUDE.\n5. PMID:41249114 — Directly studies C8orf33 mechanism in DSB repair. KEEP.\n6. PMID:41965457 — Studies C8orf33 in HCC with loss-of-function experiments and some mechanistic data. KEEP (partial mechanism).\n\nGene2pubmed papers: These are large interactome/proteome studies (BioPlex, HuRI, etc.) that may list C8ORF33 as an interactor but provide no specific mechanistic findings about C8ORF33. All are EXCLUDE for mechanistic discovery purposes — they are proteome-scale resources where C8ORF33 appears incidentally without mechanistic characterization. Same for PMID:22658674 (mRNA interactome capture listing C8ORF33 as an RBP). PMID:26949251 (Ki-67), PMID:32807901 (UFMylation/p53), PMID:21832049 (TPPP/p25), PMID:29802200 (BAD domains), PMID:29298432 (ZC3H18) — none about C8ORF33. All EXCLUDE.\n\n```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2025,\n      \"finding\": \"C8orf33 is a nuclear protein that localizes predominantly to the nucleolus and is recruited to DNA double-strand break (DSB) sites in both nuclear and nucleolar regions. C8orf33 promotes recruitment of 53BP1 to DSB sites, thereby channeling DSB repair toward non-homologous end joining (NHEJ). Mechanistically, C8orf33 antagonizes chromatin association of the KAT8 acetyltransferase at DSB sites, leading to reduced histone H4 lysine 16 acetylation (H4K16ac) levels. Loss of C8orf33 enhances KAT8 chromatin binding, increases H4K16ac, promotes recruitment of HR factors BRCA1 and RAD51, and suppresses 53BP1 accumulation, thereby shifting DSB repair pathway choice from NHEJ toward homologous recombination (HR). C8orf33 deficiency causes accelerated loss of ribosomal DNA repeats and increased cell death, demonstrating its role in safeguarding genomic integrity.\",\n      \"method\": \"Chromatin profiling, immunofluorescence microscopy of DSB recruitment, loss-of-function (siRNA/KO) with readouts of 53BP1/BRCA1/RAD51 foci, H4K16ac ChIP, DNA end resection assays, rDNA repeat stability assay\",\n      \"journal\": \"Cell death & disease\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — multiple orthogonal methods (chromatin profiling, foci assays, ChIP, functional genomic readouts) in a single study with rigorous mechanistic pathway placement\",\n      \"pmids\": [\"41249114\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2026,\n      \"finding\": \"C8orf33 knockdown in HCC cell lines reduces proliferation, migration, and tumorigenic capacity, and increases apoptosis. C8orf33 loss is accompanied by reduced mRNA and protein levels of MIF and its receptor components (CD74, CXCR4, CD44), and in xenografts reduces infiltration of CD163/CD206-positive M2-like macrophages, suggesting C8orf33 contributes to a tumor-promoting MIF signaling axis linked to immunomodulatory macrophage recruitment.\",\n      \"method\": \"siRNA knockdown in HCC cell lines, in vitro proliferation/migration/apoptosis assays, subcutaneous xenograft models, scRNA-seq, spatial transcriptomics, cell-cell communication analysis, qRT-PCR and western blot for MIF-axis components, IHC for macrophage markers\",\n      \"journal\": \"Discover oncology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2/3 — loss-of-function with defined phenotypic readout and partial pathway placement (MIF axis), single lab, correlative mechanistic link\",\n      \"pmids\": [\"41965457\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"C8orf33 is a nucleolar protein recruited to DNA double-strand break sites where it promotes NHEJ over HR by antagonizing KAT8-mediated H4K16 acetylation and facilitating 53BP1 recruitment while suppressing BRCA1/RAD51 accumulation; additionally, C8orf33 supports HCC cell survival and proliferation through a potential link to MIF-mediated macrophage immunomodulatory signaling.\"\n}\n```","stage2_raw":"```json\n{\n  \"mechanistic_narrative\": \"C8orf33 is a nucleolar nuclear protein that regulates DNA double-strand break (DSB) repair pathway choice to maintain genomic integrity. It is recruited to DSB sites where it antagonizes KAT8 acetyltransferase chromatin binding, thereby suppressing H4K16 acetylation, promoting 53BP1 recruitment, inhibiting DNA end resection, and channeling repair toward NHEJ over homologous recombination [PMID:41249114]. Loss of C8orf33 causes accelerated ribosomal DNA repeat loss and increased cell death due to inappropriate homologous recombination activity [PMID:41249114]. C8orf33 also supports hepatocellular carcinoma cell proliferation and migration at least partly through modulation of MIF-axis signaling [PMID:41965457].\",\n  \"teleology\": [\n    {\n      \"year\": 2025,\n      \"claim\": \"Establishing that C8orf33 is a nucleolar protein recruited to DSBs that promotes NHEJ resolved the unknown cellular function of this previously uncharacterized open reading frame, placing it directly in the DNA damage response.\",\n      \"evidence\": \"Live imaging, fractionation, recruitment assays at DSB sites, and loss-of-function experiments in human cells\",\n      \"pmids\": [\"41249114\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"The mechanism by which C8orf33 is recruited to DSB sites is not defined\",\n        \"No direct protein–protein interaction with 53BP1 or BRCA1 has been demonstrated\",\n        \"Whether nucleolar versus nucleoplasmic DSB repair roles are mechanistically distinct is untested\"\n      ]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Demonstrating that C8orf33 antagonizes KAT8 chromatin association and suppresses H4K16 acetylation at DSBs provided an epistatic mechanism for how it controls NHEJ-versus-HR pathway choice, linking a histone modification axis to repair outcome.\",\n      \"evidence\": \"ChIP for KAT8 and H4K16ac in C8orf33-deficient cells with pathway-specific repair readouts\",\n      \"pmids\": [\"41249114\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"Whether C8orf33 directly binds KAT8 or acts through an intermediary is unknown\",\n        \"No structural or biochemical reconstitution of the C8orf33–KAT8 antagonism exists\",\n        \"Relevance of this mechanism in non-transformed primary cells has not been tested\"\n      ]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Showing that C8orf33 loss accelerates rDNA repeat loss and increases cell death linked its nucleolar localization to a specific genomic integrity phenotype — protection of repetitive ribosomal DNA loci from aberrant recombination.\",\n      \"evidence\": \"rDNA repeat loss assay and cell death quantification in C8orf33-deficient cells\",\n      \"pmids\": [\"41249114\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Only tested in a single lab; independent replication is lacking\",\n        \"Whether rDNA instability is a direct consequence of NHEJ loss or reflects additional functions is unresolved\",\n        \"In vivo organismal consequences of rDNA instability upon C8orf33 loss are unexplored\"\n      ]\n    },\n    {\n      \"year\": 2026,\n      \"claim\": \"Linking C8orf33 to HCC cell proliferation and MIF-axis signaling revealed a potential oncogenic role independent of its characterized DSB repair function, broadening its biological significance.\",\n      \"evidence\": \"siRNA/shRNA knockdown in HCC cell lines with proliferation, migration, apoptosis assays, xenograft models, and RT-qPCR/western blot for MIF pathway components\",\n      \"pmids\": [\"41965457\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"The mechanistic connection between C8orf33 and MIF transcription/signaling is undefined\",\n        \"Whether the HCC phenotype is related to the DSB repair function or represents an independent role is unknown\",\n        \"Single-lab study without rescue experiments to confirm specificity\"\n      ]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"It remains unknown whether C8orf33 directly binds KAT8 or other chromatin factors, what structural features mediate its DSB recruitment, and how its DSB repair and MIF-axis regulatory functions are mechanistically connected.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Low\",\n      \"gaps\": [\n        \"No biochemical reconstitution or structural information for C8orf33\",\n        \"No defined protein domains or motifs with assigned function\",\n        \"Relationship between DSB repair role and tumor-promoting activity is completely uncharacterized\"\n      ]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0098772\", \"supporting_discovery_ids\": [0, 1]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005730\", \"supporting_discovery_ids\": [0]},\n      {\"term_id\": \"GO:0005634\", \"supporting_discovery_ids\": [0]},\n      {\"term_id\": \"GO:0005694\", \"supporting_discovery_ids\": [0, 1]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-73894\", \"supporting_discovery_ids\": [0, 1, 2]},\n      {\"term_id\": \"R-HSA-4839726\", \"supporting_discovery_ids\": [1]}\n    ],\n    \"complexes\": [],\n    \"partners\": [\n      \"KAT8\",\n      \"TP53BP1\"\n    ],\n    \"other_free_text\": []\n  }\n}\n```\n\n--- ROUND 2 (R2/R3, augmented corpus) ---\n\n```json\n{\n  \"mechanistic_narrative\": \"C8orf33 is a nucleolar protein recruited to DNA double-strand break (DSB) sites, where it promotes non-homologous end joining (NHEJ) by facilitating 53BP1 accumulation and antagonizing KAT8 acetyltransferase chromatin association, thereby reducing H4K16 acetylation and suppressing BRCA1/RAD51-mediated homologous recombination [PMID:41249114]. C8orf33 deficiency leads to accelerated loss of ribosomal DNA repeats and increased cell death, indicating a role in safeguarding rDNA integrity [PMID:41249114]. In hepatocellular carcinoma cells, C8orf33 knockdown reduces proliferation and tumorigenic capacity and downregulates the MIF signaling axis (MIF, CD74, CXCR4, CD44), correlating with decreased M2-like macrophage infiltration in xenograft models [PMID:41965457].\",\n  \"teleology\": [\n    {\n      \"year\": 2025,\n      \"claim\": \"The molecular function of C8orf33 was unknown; chromatin profiling and DSB recruitment assays established that it localizes to the nucleolus, is recruited to DSB sites, and channels repair toward NHEJ by antagonizing KAT8-dependent H4K16 acetylation and promoting 53BP1 recruitment, thereby safeguarding rDNA repeat stability.\",\n      \"evidence\": \"siRNA/KO in human cells with 53BP1/BRCA1/RAD51 foci quantification, H4K16ac ChIP, DNA end resection assays, and rDNA repeat stability assays\",\n      \"pmids\": [\"41249114\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"Direct physical interaction between C8orf33 and KAT8 has not been demonstrated\",\n        \"Structural basis by which C8orf33 antagonizes KAT8 chromatin association is unknown\",\n        \"Whether C8orf33 plays additional roles in nucleolar functions beyond rDNA protection is unresolved\"\n      ]\n    },\n    {\n      \"year\": 2026,\n      \"claim\": \"A role for C8orf33 in tumor cell biology was undefined; knockdown experiments in HCC cells revealed that C8orf33 supports proliferation, migration, and survival and sustains MIF-pathway signaling linked to immunomodulatory macrophage recruitment.\",\n      \"evidence\": \"siRNA knockdown in HCC cell lines with proliferation/apoptosis assays, subcutaneous xenograft models, scRNA-seq and spatial transcriptomics, qRT-PCR/western blot for MIF-axis components, IHC for macrophage markers\",\n      \"pmids\": [\"41965457\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Mechanistic link between C8orf33 and MIF transcription/signaling is correlative and not directly tested\",\n        \"Whether the pro-tumorigenic phenotype reflects C8orf33's DSB repair function or an independent pathway is unclear\",\n        \"Single-laboratory study; independent validation in additional tumor models is lacking\"\n      ]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"Whether C8orf33 directly binds KAT8 or chromatin, its structural mechanism, and the relationship between its DSB repair and tumor-promoting functions remain unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Low\",\n      \"gaps\": [\n        \"No structural or biophysical characterization of C8orf33 exists\",\n        \"No direct binding partner has been biochemically validated\",\n        \"The contribution of NHEJ-promoting activity to rDNA maintenance versus general genome integrity is unresolved\"\n      ]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0098772\", \"supporting_discovery_ids\": [0]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005730\", \"supporting_discovery_ids\": [0]},\n      {\"term_id\": \"GO:0005634\", \"supporting_discovery_ids\": [0]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-73894\", \"supporting_discovery_ids\": [0]}\n    ],\n    \"complexes\": [],\n    \"partners\": [\n      \"KAT8\",\n      \"TP53BP1\"\n    ],\n    \"other_free_text\": []\n  }\n}\n```"}