BRCA1 and ovarian neoplasm: Only a small proportion of BRCA1 and BRCA2 germline mutation-associated breast and ovarian tumors (n = 3, 3%) and nonBRCA ovarian tumors (n = 8, 4%) had over 20% of mutations attributed to any signatures other than Signatures 1,3, and 5, with Signatures 2 (APOBEC) and 6 (defective mismatch repair) observed.