Of note, Signature 1 is the result of an endogenous mutational process and is a common signature in most human cancer types, whereas Signature 3 indicates defective homology-directed double-strand DNA break repair and is associated with germline and somatic BRCA1 and BRCA2 mutations in breast, pancreatic, and ovarian cancers [38]. This evidence concerns the gene BRCA1 and ovarian cancer.