BRCA1 and Familial prostate cancer: Men with lethal prostate cancer are more likely to have germline mutations in DNA repair genes33,34; however, the association of HDR gene defects with response to abiraterone and enzalutamide is conflicting.17,29,30 Approximately one third of patients had germline and/or somatic deleterious mutations in or CN loss of BRCA1, BRCA2, or ATM before therapy, with some patients having more than one mutation (Figs 1C and 1D and Data Supplement).