For carriers of pathogenic variants in BRCA1, the average cumulative risks by age 80 years is 72% (95% confidence interval 65–79%) for breast cancer and 44% (36–53%) for ovarian cancer, and the corresponding estimates for BRCA2 are 69% (61–77%) and 17% (11–25%) respectively [4]. This evidence concerns the gene BRCA2 and breast cancer.