Contralateral prophylactic mastectomy (CPM; surgical removal of the nonaffected breast for women with unilateral breast cancer) has not been shown to improve survival rates, but may decrease the risk of contralateral cancers in certain high-risk women; it is considered a clinically appropriate option for breast cancer patients with known BRCA1/2 mutations, significant family history, or high-risk histology [32–38]. The gene discussed is BRCA1; the disease is breast cancer.