The antitumour activity observed against tumours with ATM, PALB2, FANCA, or CHEK2 aberrations suggest that PARP inhibitors might have a role as single drug therapies or in rational combinations against these other subtypes of metastatic prostate cancer, although further data are needed to precisely assess the clinical relevance of each of these different DDR gene aberrations in prostate cancer. The gene discussed is CHEK2; the disease is prostate cancer.