BRCA1 and breast cancer: In this study, we report the prevalence of BRCA1/2 mutations in patients with high‐risk breast cancer from Inner Mongolia and Jilin, China, as part of a nationwide project on the detection of BRCA1/2 mutations in Chinese patients with hereditary breast cancer, led by the 307th Hospital of the Chinese People's Liberation Army and involving a number of breast cancer clinics across the country.