[17] Sokolenko Sokolenko AP AP Double heterozygotes among breast cancer patients analyzed for BRCA1, CHEK2, ATM, NBN/NBS1, and BLM germ-line mutations Double heterozygotes among breast cancer patients analyzed for BRCA1, CHEK2, ATM, NBN/NBS1, and BLM germ-line mutations Breast Cancer Res Treat Breast Cancer Res Treat 2014 2014 145 145 2 2 553 553 62 62 24800916 24800916. The gene discussed is CHEK2; the disease is breast cancer.