The current phase Ib combination trial with enzalutamide and venetoclax in patients with mCRPC was motivated by our preclinical data that implicates BCL-2 as a strong driver of castration resistance [11, 35], availability of potent and selective BCL-2 inhibitor venetoclax, clinical approval of venetoclax in hematological malignancies [30–32], and emerging clinical trials of venetoclax in solid tumors such as breast cancer [33, 34]. The gene discussed is BCL2; the disease is breast cancer.