It was shown that retinoblastoma protein 1 (RB1), a cell cycle suppressor and the CUB And Sushi Multiple Domains 1 (CSMD1), a tumor suppressor that control cell proliferation, invasion, and migration, are more frequently deleted in Black/African American breast cancer patients (14.5% and 8.6%, respectively) as compared to White patients (8.7% and 4.1%, respectively). The gene discussed is CSMD1; the disease is breast carcinoma.