As DS-1594a·HCl and DS-1594a·succinate treatment disrupted Menin-associated protein complexes and MLL fusion-driven gene expression, we assessed the chromatin occupancy of Menin and MLL1 proteins and histone modifications important in MLL1-r leukemia, including H3K79me2 and H3K4me3. The gene discussed is MEN1; the disease is leukemia.