{"entity":{"id":"cdkn1b","kind":"target","name":"CDKN1B","aka":["cyclin dependent kinase inhibitor 1B","Cyclin-dependent kinase inhibitor 1B","KIP1","P27KIP1"],"tldr":"CDKN1B (Cyclin-dependent kinase inhibitor 1B) is a gene whose normal job is to hold cell growth in check. The public catalogues list it as a drug target, an oncogene driver, a tumour suppressor and a biomarker, and clinical evidence ties its variants to diagnosis, prognosis or drug response. Tied to Thyroid cancer, Prostate cancer, Breast cancer and 5 more.","summary":"Important regulator of cell cycle progression. Inhibits the kinase activity of CDK2 bound to cyclin A, but has little inhibitory activity on CDK2 bound to SPDYA. Involved in G1 arrest.\n\nCIViC holds 2 clinical evidence items and 0 assertions across 2 variants, naming Lapatinib, Cisplatin and Fluorouracil. Open Targets scores its association with cancer at 0.81 (direct and indirect evidence; datatypes genetic literature 0.73, affected pathway 0.76, literature 0.99, genetic association 0.75, somatic mutation 0.90, animal model 0.54). IntOGen calls it a driver in 12 cohorts (1 activating, 11 loss-of-function), covering Invasive Breast Carcinoma, Hepatocellular Carcinoma, Plasma Cell Myeloma, Prostate Adenocarcinoma, Small Intestinal Carcinoma.","asOf":"2026-09-23","links":[{"label":"HGNC HGNC:1785","url":"https://www.genenames.org/data/gene-symbol-report/#!/hgnc_id/HGNC:1785"},{"label":"UniProt P46527","url":"https://www.uniprot.org/uniprotkb/P46527/entry"},{"label":"NCBI Gene 1027","url":"https://www.ncbi.nlm.nih.gov/gene/1027"},{"label":"Ensembl ENSG00000111276","url":"https://www.ensembl.org/Homo_sapiens/Gene/Summary?g=ENSG00000111276"}],"tags":["cancer-genes-wave"],"related":["civic","open-targets","intogen"],"cancers":["thyroid","prostate","breast-cancer","neuroendocrine","head-and-neck","multiple-myeloma","hcc","small-bowel"],"sections":[],"technologies":[],"targets":[],"drugs":[],"companies":[],"institutions":[],"pathways":["prostate-cancer-signalling"],"terms":[],"trials":[],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":["Written by scripts/fetch-cancer-genes.ts from CIViC, Open Targets, IntOGen, HGNC and UniProt; the function text is UniProt's, condensed and in UK spelling. Roles: CIViC lists 3 therapies; IntOGen calls it an activating (Act) driver in 1 cohort; IntOGen calls it a loss-of-function (LoF) driver in 11 cohorts; CIViC holds 2 clinical evidence items on its variants. Evidence tier \"clinical-evidence\" is the strongest of those signals.","Prevalence not recorded: none of the sources gives a positivity rate."],"provenance":{"editedBy":"scripts/fetch-cancer-genes.ts (CIViC, Open Targets, IntOGen, HGNC, UniProt)","editedOn":"2026-09-23"},"symbol":"CDKN1B","role":["drug-target","oncogene-driver","tumour-suppressor","biomarker"],"evidenceTier":"clinical-evidence","sources":[{"label":"HGNC HGNC:1785","url":"https://www.genenames.org/data/gene-symbol-report/#!/hgnc_id/HGNC:1785","note":"approved symbol, name, aliases, locus and cross-references (hgnc_complete_set.txt)"},{"label":"UniProt P46527","url":"https://www.uniprot.org/uniprotkb/P46527/entry","note":"protein name, function text, keywords and locations (REST API)"},{"label":"CIViC gene CDKN1B","url":"https://civicdb.org/features/914","note":"2 evidence items, 0 assertions, 2 variants; diseases: Breast Cancer, Head And Neck Squamous Cell Carcinoma (GraphQL API, CC0)"},{"label":"Open Targets ENSG00000111276","url":"https://platform.opentargets.org/target/ENSG00000111276/associations","note":"association with cancer (MONDO_0004992) 0.81; per-cancer scores at or above 0.5: prostate cancer 0.63, thyroid cancer 0.65, neuroendocrine neoplasm 0.62, acute lymphoblastic leukaemia 0.53, non-Hodgkin lymphoma 0.56, breast cancer 0.63 (GraphQL API, CC0)"},{"label":"IntOGen CDKN1B","url":"https://www.intogen.org/search?gene=CDKN1B","note":"driver in 12 cohorts (Act 1, LoF 11); Compendium_Cancer_Genes.tsv release 20240920, CC0 1.0"}],"specificity":"tumour-specific","distribution":"many-types","specificityNote":"Tumour-specific alteration: the catalogues call it an oncogene driver (IntOGen cohort analysis finds it activated more often than chance) and a tumour suppressor (IntOGen finds it knocked out more often than chance), so the direction differs between cohorts but the alteration is somatic either way; what a medicine would aim at or exploit is the altered form or its loss, absent from normal cells; no corpus medicine is aimed at it yet. HPA CDKN1B: RNA low tissue specificity; high antibody staining in 9 normal tissues; highest cancer staining carcinoid (1 of 4 high). Distribution: 8 cancer families in the corpus carry a prevalence row, label threshold or catalogue link for it (Thyroid cancer, Prostate cancer, Breast cancer (all types), Neuroendocrine tumours, Head and neck squamous cell carcinoma, Multiple myeloma, Hepatocellular carcinoma and more); Open Targets associates it with 6 specific cancer types at or above 0.5 (multiple endocrine neoplasia type 4, prostate carcinoma, hereditary neoplastic syndrome, thyroid gland carcinoma, pituitary gland adenoma, thyroid cancer). (Rule 6 of scripts/fetch-target-specificity.ts.)","specificitySources":[{"label":"UniProt P46527","url":"https://www.uniprot.org/uniprotkb/P46527/entry","note":"protein name, function text, keywords and locations (REST API)"},{"label":"CIViC gene CDKN1B","url":"https://civicdb.org/features/914","note":"2 evidence items, 0 assertions, 2 variants; diseases: Breast Cancer, Head And Neck Squamous Cell Carcinoma (GraphQL API, CC0)"},{"label":"IntOGen CDKN1B","url":"https://www.intogen.org/search?gene=CDKN1B","note":"driver in 12 cohorts (Act 1, LoF 11); Compendium_Cancer_Genes.tsv release 20240920, CC0 1.0"},{"label":"Human Protein Atlas CDKN1B tissue","url":"https://www.proteinatlas.org/ENSG00000111276-CDKN1B/tissue","note":"RNA tissue and blood lineage specificity, normal tissue antibody staining (version 25.1, CC BY-SA 3.0)"},{"label":"Open Targets ENSG00000111276 associations","url":"https://platform.opentargets.org/target/ENSG00000111276/associations","note":"cancer associations at or above 0.5 (CC0)"}],"hgnc":"HGNC:1785","ensembl":"ENSG00000111276","uniprot":"P46527","entrez":"1027","firstDescribed":1994,"firstDescribedBasis":"sequence","firstDescribedNote":"Earliest sequence paper UniProt cites for the protein: Polyak et al, Cell, 1994, \"Cloning of p27Kip1, a cyclin-dependent kinase inhibitor and a potential mediator of extracellular antimitogenic signals\".","firstDescribedSource":"https://pubmed.ncbi.nlm.nih.gov/8033212/","biology":"Important regulator of cell cycle progression. Inhibits the kinase activity of CDK2 bound to cyclin A, but has little inhibitory activity on CDK2 bound to SPDYA. Involved in G1 arrest. Potent inhibitor of cyclin E- and cyclin A-CDK2 complexes. Forms a complex with cyclin type D-CDK4 complexes and is involved in the assembly, stability, and modulation of CCND1-CDK4 complex activation. Acts either as an inhibitor or an activator of cyclin type D-CDK4 complexes depending on its phosphorylation state and/or stoichiometry. Location: Nucleus; Cytoplasm; Endosome (UniProt). Locus 12p13.1 (HGNC).","whereFound":["Thyroid cancer: Open Targets association 0.65 with thyroid cancer (MONDO_0002108)","Prostate cancer: Open Targets association 0.63 with prostate cancer (MONDO_0008315); IntOGen driver in 4 cohorts (PRAD)","Breast cancer: Open Targets association 0.63 with breast cancer (MONDO_0007254); CIViC evidence names this disease","Neuroendocrine tumours: Open Targets association 0.62 with neuroendocrine neoplasm (MONDO_0019496)","Head and neck squamous cell carcinoma: CIViC evidence names this disease","Multiple myeloma: IntOGen driver in 2 cohorts (PCM)","Prostate cancer: deep deletion 1-4% depending on disease state"],"targetClass":"tumor-suppressor","prevalence":[{"cancerId":"prostate","pct":"1-4","measure":"Deep deletion","source":"https://www.cbioportal.org/study/summary?id=prad_tcga_pan_can_atlas_2018","note":"cBioPortal deep deletion: 20 of 489, 4.1%, in prad_tcga_pan_can_atlas_2018; 22 of 1,013, 2.2%, in prad_p1000; 13 of 424, 3.1%, in prad_mcspc_mskcc_2020; 71 of 2,260, 3.1%, in prostate_msk_2024; 52 of 1,465, 3.5%, in prad_cdk12_mskcc_2020; 13 of 444, 2.9%, in prad_su2c_2019."}]},"route":"/targets/cdkn1b/","neighbours":{"collection":[{"id":"civic","kind":"collection","name":"CIViC","route":"/collections/civic/"},{"id":"intogen","kind":"collection","name":"IntOGen","route":"/collections/intogen/"},{"id":"open-targets","kind":"collection","name":"Open Targets Platform","route":"/collections/open-targets/"}],"cancer":[{"id":"breast-cancer","kind":"cancer","name":"Breast cancer (all types)","route":"/cancers/breast-cancer/"},{"id":"head-and-neck","kind":"cancer","name":"Head and neck squamous cell carcinoma","route":"/cancers/head-and-neck/"},{"id":"hcc","kind":"cancer","name":"Hepatocellular carcinoma","route":"/cancers/hcc/"},{"id":"multiple-myeloma","kind":"cancer","name":"Multiple myeloma","route":"/cancers/multiple-myeloma/"},{"id":"neuroendocrine","kind":"cancer","name":"Neuroendocrine tumours","route":"/cancers/neuroendocrine/"},{"id":"prostate","kind":"cancer","name":"Prostate cancer","route":"/cancers/prostate/"},{"id":"small-bowel","kind":"cancer","name":"Small intestine cancer (small bowel adenocarcinoma)","route":"/cancers/small-bowel/"},{"id":"thyroid","kind":"cancer","name":"Thyroid cancer","route":"/cancers/thyroid/"}],"pathway":[{"id":"prostate-cancer-signalling","kind":"pathway","name":"Prostate cancer (KEGG map)","route":"/pathways/prostate-cancer-signalling/"}]}}