Importantly, prostate cancer poses a particular challenge for more naive single measure approaches that produce genomic instability scores, since copy number changes are pervasive (and therefore nonspecific to HRR-deficient genomes) and there are multiple classes of DDR defect associated with genome instability (including CDK12 mutations) which are not associated with disease response to PARP inhibition41. This evidence concerns the gene CDK12 and prostate carcinoma.