Taken together, our results show that MLL-ENL can induce a leukaemic transcriptional program in Hoxb8-FL cells, but only if the cells are taken out of their Flt3L and β-estradiol self-renewal culture condition, reminiscent of previous studies showing that MLL-ENL did not induce AML in mice when transduced into highly purified HSCs9 and MLL-AF9 did not cause AML in either HSCs or CMPs when myeloid differentiation was compromised by C/EBPα deletion29. This evidence concerns the gene MLLT3 and acute myeloid leukemia.