Bafilomycin A1 (BafA1), an inhibitor of the vacuolar H+ ATPase, blocks lysosomal degradation and eventually prevents autophagosome fusion with lysosomes.7 Autophagy has been thought to be dysregulated in AML, suggesting a potentially important role for autophagy in AML pathogenesis.8, 13, 14 The level of autophagic flux under basal conditions was therefore measured in malignant murine AML cells expressing exogenous MLL-AF9, compared with their healthy BM counterpart in vitro. The gene discussed is KMT2A; the disease is acute myeloid leukemia.