Venetoclax has been found to have high antileukemia activity in patients with chronic lymphocytic leukemia (CLL) [56] and has been reported to have preclinical activities in estrogen receptor–positive breast cancer, acute myeloid leukemia, early T-cell progenitor leukemia, and Myc-driven B-cell lymphomas 27, 52, 53, 54, 55. The gene discussed is ESR1; the disease is B-cell chronic lymphocytic leukemia.