Venetoclax (Fig. 1 ▸) is a highly selective BCL-2 inhibitor first approved in the United States, and later in the EU, for monotherapy of chronic lymphocytic leukaemia in patients with 17p deletion or TP53 mutation (Salem et al., 2017 ▸; Deeks, 2016 ▸) and later the approval extended to acute myeloid leukaemia and small lymphocytic lymphoma (European Medicines Agency, 2016 ▸). The gene discussed is BCL2; the disease is B-cell chronic lymphocytic leukemia.