CHEK2 and breast cancer: Our investigation revealed that 52 (37.4%) out of 139 genetically tested BBC patients were shown to carry germline PVs in high- and intermediate-penetrance BC susceptibility genes such as BRCA1, BRCA2, PTEN, PALB2, CHEK2, ATM, RAD51C. Interestingly, a noteworthy correlation between PVs in PALB2 or CHEK2 and BBCs was observed.