CHEK2 and cancer: Hereditary predisposition to breast and/or ovarian (HBOC) cancer indication accounts for 65% of the identified pathogenic variants (BRCA1, BRCA2, PALB2, ATM, CHEK2, NBN, RAD51C, and RAD51D); Lynch syndrome (MLH1, MSH2, EPCAM, PMS2 and MSH6) represented 24.3%, and familial adenomatous polyposis (APC) 1.9% of the variants (Figure 3).