GFI1 and acute myeloid leukemia: We previously demonstrated that LSD1 inhibitor-induced upregulation of a myeloid differentiation program in THP1 AML cells is dependent upon drug-induced physical separation of LSD1 from GFI1 rather than inhibition of the enzymatic activity of LSD1, and that expression of a GFI1.ZNF-LSD1 fusion protein which is resistant to drug-induced physical separation is sufficient to confer cellular resistance to LSD1 inhibitors [8].