A recent population-based matched analysis by Hu et al. demonstrated that the prevalence of 12 established breast cancer-predisposition genes (ATM, BARD1, BRCA1, BRCA2, CDHS1, CHEKs, NF1, PALB2, PTEN, RAD51C and TP53) is closer to 5% among women with breast cancer [18]. Here, BRCA1 is linked to breast cancer.