HRD has been observed not only in ovarian cancer patients with germline or somatic BRCA1 or BRCA2 mutations but also in those with epigenetic silencing of BRCA1 or loss of function of other genes, such as ATM, ATR, BARD, BRIP, EMSY, PALB2, RAD51, and Fanconi Anemia Complementation Group genes [25,26,27,28,29,30]. Here, BRCA1 is linked to ovarian cancer.