DOT1L, however, is dispensable for BCR-ABL, E2A-HLF, E2A-PBX2 leukemias, and leukemia generated by ectopic retroviral overexpression of HOXA9/MEIS1 (Chang et al., 2010; Jo et al., 2011; Richter et al., 2021). Here, HOXA9 is linked to leukemia.