Interestingly, global assessment of H3K4 methylation associated with LSD1 showed an aberrant increase in euchromatic H3K4me2 compared to active H3K4me3 marks in both human and mouse ETP-ALL cells which suggests a unique repression mechanism of ‘poised” genes previously observed in hematopoietic progenitors [12, 13], that could be appropriated by the ZEB/LSD1 complex to repress the expression of certain key genes. This evidence concerns the gene KDM1A and acute lymphoblastic leukemia.