BRCA1 and breast cancer: According to various studies(62-64), mutations in genes thatpredispose to breast cancer are classified as high risk when they increase therisk by five times or more (e.g., mutations in the BRCA1, BRCA2, TP53, and PTENgenes) and as intermediate risk when they increase the risk by 1.5-5.0 times(e.g., mutations in the ATM, CHEK2, and BARD1 genes).