Along with mounting evidence for the role of BCL-2 in AML cell survival, early preclinical studies into venetoclax as a monotherapy in AML cell lines, patient samples, and a murine xenograft model demonstrated on-target cell killing9, with particular sensitivity to venetoclax seen in AML cells harboring the MLL fusion genes and in acute promyelocytic leukemia (APL) cells85. This evidence concerns the gene BCL2 and acute promyelocytic leukemia.