BRCA1 and ovarian cancer: Among the 10–16% of PDAC cases with family history, only 5% have inherited syndromes such as Peutz–Jeghers syndrome, familial atypical multiple-mole melanoma, hereditary nonpolyposis colorectal cancer, and hereditary breast and ovarian cancer, which arise from germ line mutations in STK11, p16, MLH1, and BRCA1/2, as well as other mismatch repair genes.19,20 Moreover, a strong family history (multiple first-degree relatives affected) confers increased risk even without such germ line genetic mutations.