KMT2A and acute myeloid leukemia: While the reasons underlying the different results need further investigations, LSD1 on the other hand underpins retinoic acid receptor (RARa)-driven repression of myeloid differentiation-associated genes in AML through decreasing the level of H3K4me2.50 These results may suggest a more generic role of H3K4 methylation in AML pathogenesis, which may not be specific to MLL leukaemia.