# CDK12

Source: https://onco.cc/targets/cdk12/  
OnCo record `cdk12` (Target). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

CDK12 (Cyclin-dependent kinase 12) 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 tumour suppressor, a biomarker and a fusion partner, and clinical evidence ties its variants to diagnosis, prognosis or drug response. Tied to Prostate cancer, Ovarian cancer, Breast cancer and 5 more.

## Summary

Cyclin-dependent kinase that phosphorylates the C-terminal domain (CTD) of the large subunit of RNA polymerase II (POLR2A), thereby acting as a key regulator of transcription elongation. Regulates the expression of genes involved in DNA repair and is required for the maintenance of genomic stability. Preferentially phosphorylates 'Ser-5' in CTD repeats that are already phosphorylated at 'Ser-7', but can also phosphorylate 'Ser-2'.

CIViC holds 9 clinical evidence items and 0 assertions across 4 variants, naming Olaparib, Talazoparib, Enzalutamide and Rucaparib and others. Open Targets scores its association with cancer at 0.80 (direct and indirect evidence; datatypes clinical 0.17, affected pathway 0.76, literature 0.99, genetic association 0.32, somatic mutation 0.92). IntOGen calls it a driver in 17 cohorts (2 activating, 15 loss-of-function), covering Bladder Urothelial Carcinoma, Renal Clear Cell Carcinoma, Cervical Squamous Cell Carcinoma, Diffuse Large B-Cell Lymphoma, NOS, Melanoma, Ovarian Epithelial Tumour and others.

## Fields

- Kind: Target
- Last checked: 2026-09-23
- Also known as: cyclin dependent kinase 12; Cyclin-dependent kinase 12; CRK7; KIAA0904; CRKRS
- Tags: cancer-genes-wave
- Symbol: CDK12
- Class: kinase
- Biology: Cyclin-dependent kinase that phosphorylates the C-terminal domain (CTD) of the large subunit of RNA polymerase II (POLR2A), thereby acting as a key regulator of transcription elongation. Regulates the expression of genes involved in DNA repair and is required for the maintenance of genomic stability. Preferentially phosphorylates 'Ser-5' in CTD repeats that are already phosphorylated at 'Ser-7', but can also phosphorylate 'Ser-2'. Required for RNA splicing, possibly by phosphorylating SRSF1/SF2. Involved in regulation of MAP kinase activity, possibly leading to affect the response to oestrogen inhibitors. Location: Nucleus; Nucleus speckle (UniProt). Locus 17q12 (HGNC).
- Where found: Prostate cancer: Open Targets association 0.67 with prostate cancer (MONDO_0008315); CIViC evidence names this disease; Ovarian cancer: Open Targets association 0.58 with ovarian cancer (MONDO_0008170); CIViC evidence names this disease; Breast cancer: CIViC evidence names this disease; Bladder & urothelial cancer: IntOGen driver in 1 cohort (BLCA); Renal cell carcinoma: IntOGen driver in 1 cohort (CCRCC); Cervical cancer: IntOGen driver in 1 cohort (CESC)

## 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 0.17; IntOGen calls it an activating (Act) driver in 2 cohorts; IntOGen calls it a loss-of-function (LoF) driver in 15 cohorts; CIViC holds 9 clinical evidence items on its variants; UniProt disease notes describe a translocation or gene fusion involving the gene. Evidence tier "clinical-evidence" is the strongest of those signals.
- Prevalence not recorded: none of the sources gives a positivity rate.

## Sources

- HGNC HGNC:24224: https://www.genenames.org/data/gene-symbol-report/#!/hgnc_id/HGNC:24224
- UniProt Q9NYV4: https://www.uniprot.org/uniprotkb/Q9NYV4/entry
- NCBI Gene 51755: https://www.ncbi.nlm.nih.gov/gene/51755
- Ensembl ENSG00000167258: https://www.ensembl.org/Homo_sapiens/Gene/Summary?g=ENSG00000167258

## 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: [Bladder & urothelial cancer](https://onco.cc/cancers/urothelial/), [Breast cancer (all types)](https://onco.cc/cancers/breast-cancer/), [Cervical cancer](https://onco.cc/cancers/cervical/), [Gastric & gastro-oesophageal junction cancer](https://onco.cc/cancers/gastric/), [Ovarian cancer](https://onco.cc/cancers/ovarian/), [Prostate cancer](https://onco.cc/cancers/prostate/), [Renal cell carcinoma](https://onco.cc/cancers/rcc/), [Skin cancer (all types)](https://onco.cc/cancers/skin-cancer/)

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JSON: https://onco.cc/api/v1/entities/cdk12.json