With the application of next-generation sequencing (NGS) over the past 10 years, many non-BRCA breast cancer susceptibility genes have been identified in succession, such as ATM, CHEK2, PALB2 and TP53. Multigene testing is of great significance for breast cancer risk prediction, molecular typing (especially for triple-negative breast cancer) and selection of precise treatment options. The gene discussed is CHEK2; the disease is breast cancer.