Along with BRCA1 and BRCA2, multiple HRR genes, including ATM, BARD1, BRIP1, CHEK2 (encodes CHK2), MRE11A, PALB2, RAD50, RAD51C, and RAD51D, are also implicated in hereditary cancer risk and are recently considered new potential biomarkers in patients with non-gBRCA HRR gene mutations (112). Here, CHEK2 is linked to hereditary cancer.