STK11 and breast cancer: While BRCA1 and BRCA2 mutations are well-known germline mutations associated with an increased risk of breast cancer, several other non-BRCA genes can also harbor germline mutations linked to breast cancer susceptibility—for example, TP53, PTEN, STK11, PALB2, CHEK2, ATM, RAD51C, and RAD51D genes (Wang et al., 2021).