While rare mutations in some breast cancer susceptibility genes such as BRCA1 and BRCA2 with moderate to high penetrance have been shown to play a distinct role in breast cancer etiology by ER status [11–13], genome-wide association studies (GWAS) have additionally reported that common variants associated with breast cancer risk differ between ER subtypes [14–21]. The gene discussed is BRCA2; the disease is breast carcinoma.