In this study, therefore, we investigated pathogenic germline variants in 11 genes implicated in hereditary breast cancer, which were BRCA1, BRCA2, TP53, PTEN, CDH1, STK11, NF1, PALB2, ATM, CHEK2, and NBN1,11–18, for 1995 unselected Japanese women with breast cancer, using targeted-capture sequencing of pooled DNA (Supplementary Fig. 1a). The gene discussed is CHEK2; the disease is breast cancer.