BRCA2 and breast cancer: Breast cancer is a molecularly heterogeneous disorder associated with high lethal malignant tumors among women worldwide.[1,2] Many kinds of dangerous factors, such as the genetic, lifestyle, ethnicity, environment, region, et al. are related to breast cancer.[3] Several studies have reported that the genetic factors related to breast cancer, genetic factors play an important role in breast cancer development, including BRCA1, BRCA2.[4,5] However, mechanisms of these associations remain unclear.