CHEK2 and breast cancer: Our evidence for an additional recessively inherited major breast cancer-susceptibility gene, after considering the effects of PVs in BRCA1, BRCA2, PALB2, CHEK2, ATM, and TP53, is consistent with the results from previous analyses.12, 13, 14, 15 The best fitting model predicted age-specific FRRs consistent with the observed FRRs by epidemiological studies.