# CHEK2

Source: https://onco.cc/targets/chek2/  
OnCo record `chek2` (Target). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

CHEK2 (Serine/threonine-protein kinase Chk2) is a protein kinase, an enzyme that switches other proteins on by adding phosphate groups. The public catalogues list it as a drug target, an oncogene driver, a biomarker and a DNA repair gene, and clinical evidence ties its variants to diagnosis, prognosis or drug response. Tied to Breast cancer, Prostate cancer, Sarcomas and 5 more.

## Summary

Serine/threonine-protein kinase which is required for checkpoint-mediated cell cycle arrest, activation of DNA repair and apoptosis in response to the presence of DNA double-strand breaks. May also negatively regulate cell cycle progression during unperturbed cell cycles. Following activation, phosphorylates numerous effectors preferentially at the consensus sequence [L-X-R-X-X-S/T].

CIViC holds 9 clinical evidence items and 0 assertions across 6 variants, naming Olaparib, Enzalutamide and Talazoparib. Open Targets scores its association with cancer at 0.91 (direct and indirect evidence; datatypes genetic literature 0.86, clinical 0.19, affected pathway 0.76, literature 0.99, genetic association 0.95, somatic mutation 0.88). IntOGen calls it a driver in 1 cohort (1 activating, 0 loss-of-function), covering Invasive Breast Carcinoma.

## Fields

- Kind: Target
- Last checked: 2026-09-23
- Also known as: checkpoint kinase 2; Serine/threonine-protein kinase Chk2; CDS1; CHK2; HuCds1; PP1425; bA444G7; RAD53
- Tags: cancer-genes-wave
- Symbol: CHEK2
- Class: kinase
- Biology: Serine/threonine-protein kinase which is required for checkpoint-mediated cell cycle arrest, activation of DNA repair and apoptosis in response to the presence of DNA double-strand breaks. May also negatively regulate cell cycle progression during unperturbed cell cycles. Following activation, phosphorylates numerous effectors preferentially at the consensus sequence [L-X-R-X-X-S/T]. Regulates cell cycle checkpoint arrest through phosphorylation of CDC25A, CDC25B and CDC25C, inhibiting their activity. Inhibition of CDC25 phosphatase activity leads to increased inhibitory tyrosine phosphorylation of CDK-cyclin complexes and blocks cell cycle progression. May also phosphorylate NEK6 which is involved in G2/M cell cycle arrest. Location: Nucleus; Nucleus, PML body; Nucleus, nucleoplasm (UniProt). Locus 22q12.1 (HGNC).
- Where found: Breast cancer: Open Targets association 0.87 with breast cancer (MONDO_0007254); CIViC evidence names this disease; Prostate cancer: Open Targets association 0.80 with prostate cancer (MONDO_0008315); CIViC evidence names this disease; Sarcomas: Open Targets association 0.75 with sarcoma (MONDO_0005089); Colorectal cancer: Open Targets association 0.74 with colorectal cancer (MONDO_0005575); Ovarian cancer: Open Targets association 0.73 with ovarian cancer (MONDO_0008170); Lung cancer: Open Targets association 0.69 with lung cancer (MONDO_0008903)

## 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: Open Targets known-drug datatype score 0.19; IntOGen calls it an activating (Act) driver in 1 cohort; CIViC holds 9 clinical evidence items on its variants; UniProt keyword "DNA repair". Evidence tier "clinical-evidence" is the strongest of those signals.
- Prevalence not recorded: none of the sources gives a positivity rate.

## Sources

- HGNC HGNC:16627: https://www.genenames.org/data/gene-symbol-report/#!/hgnc_id/HGNC:16627
- UniProt O96017: https://www.uniprot.org/uniprotkb/O96017/entry
- NCBI Gene 11200: https://www.ncbi.nlm.nih.gov/gene/11200
- Ensembl ENSG00000183765: https://www.ensembl.org/Homo_sapiens/Gene/Summary?g=ENSG00000183765

## Connected records

- collections: [CIViC](https://onco.cc/collections/civic/), [IntOGen](https://onco.cc/collections/intogen/), [Open Targets Platform](https://onco.cc/collections/open-targets/)
- cancers: [Breast cancer (all types)](https://onco.cc/cancers/breast-cancer/), [Colorectal cancer](https://onco.cc/cancers/colorectal/), [Gastric & gastro-oesophageal junction cancer](https://onco.cc/cancers/gastric/), [Lung cancer (all types)](https://onco.cc/cancers/lung-cancer/), [Ovarian cancer](https://onco.cc/cancers/ovarian/), [Prostate cancer](https://onco.cc/cancers/prostate/), [Sarcomas (soft tissue, bone, GIST)](https://onco.cc/cancers/sarcoma/), [Thyroid cancer](https://onco.cc/cancers/thyroid/)
- pathways: [Double-strand break repair: HR versus end joining](https://onco.cc/pathways/homologous-recombination-repair/)
- key papers: [Association of clonal haematopoiesis in DNA repair genes with prostate cancer plasma cell-free DNA testing interference](https://onco.cc/key-papers/paper-jensen-clonal-haematopoiesis-cfdna-interference-prostate-jama-oncol-2021/), [Genomic analysis of circulating tumour DNA in 3,334 patients with advanced prostate cancer identifies targetable BRCA alterations and AR resistance mechanisms](https://onco.cc/key-papers/paper-tukachinsky-ctdna-3334-advanced-prostate-ccr-2021/), [Inherited DNA-repair gene mutations in men with metastatic prostate cancer](https://onco.cc/key-papers/paper-pritchard-inherited-dna-repair-metastatic-prostate-nejm-2016/), [Intraductal and ductal histology and lymphovascular invasion are associated with germline DNA-repair gene mutations in prostate cancer](https://onco.cc/key-papers/paper-isaacsson-velho-intraductal-germline-dna-repair-prostate-2018/), [Prevalence of germline variants in prostate cancer and implications for current genetic testing guidelines](https://onco.cc/key-papers/paper-nicolosi-germline-variants-prostate-testing-guidelines-jama-oncol-2019/)
- biomarkers: [Homologous recombination repair gene mutation in prostate cancer](https://onco.cc/biomarkers/hrr-gene-mutation/)
- terms: [Checkpoint (two meanings)](https://onco.cc/terms/checkpoint/)

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