In 8086 patients with breast cancer, there were 7591 patients without germline alterations, 116 patients (1.4%) with germline BRCA1 alterations, 176 (2.2%) with germline BRCA2 alterations, 69 (0.9%) with germline ATM alterations, 54 (0.7%) with germline PALB2 alterations, and 80 (1.0%) with germline CHEK2 alterations. This evidence concerns the gene CHEK2 and breast cancer.