OICR-9429 antagonizes the WDR5–MLL interaction, selectively inhibited proliferation, and induced differentiation in human AML cells [191]; in contrast, MM-401 targets the MLL1 H3K4 methyltransferase activity and was able to inhibit MLL1 activity by blocking MLL1–WDR5 interaction and complex assembly, specifically blocking proliferation of MLL cells by inducing cell-cycle arrest, apoptosis, and myeloid differentiation without general toxicity to normal bone marrow cells or non-MLL cells [192]. The gene discussed is WDR5; the disease is acute myeloid leukemia.