CHEK2 and breast cancer: Most gene panels include high-penetrance genes, such as BRCA1, BRCA2, CDH1, PALB2, PTEN, STK11, and TP53, and moderate-penetrance genes, such as ATM, BRIP1, CHEK2, FANCD2, RAD51C, NBN, and PMS2, which also associates with lifetime BC risk (29).