CDK12 defects are present in 6% of mCRPC19 patients and are often biallelic.32CDK12 is a kinase involved in HRR but is also key to maintain genomic stability.32 Four retrospective series have demonstrated the clinical aggressiveness of CDK12-inactivated prostate cancer tumours, which often present Gleason grade groups 4 and 5 and metastases at diagnosis. The gene discussed is CDK12; the disease is prostate cancer.