BRCA1 and breast cancer: BRCA1 and BRCA2 are the most characterized breast cancer susceptibility genes, and women carrying a germline mutation in BRCA1/2 have an estimated 70% and 20%‐40% risk of developing breast cancer and ovarian cancer during their lifetime, respectively.3, 4 Studies indicate that breast cancer with an inherit deleterious germline BRCA1/2 mutation, not only face a high risk of developing an ipsilateral5 or contralateral breast cancer,6 but also encounter an elevated risk of developing ovarian cancer.7 Therefore, intensively preclinical and clinical researches are conducted in this field.