MEIS1 and acute myeloid leukemia: In parallel, DS-1594a·succinate greatly reduced expression of MLL-fusion target genes, MEIS1 and HOXA9, dose dependently in patient-derived MLL1-r + AML cells (Fig. 3C), as in NPM1c AML patient-derived cells (AML#7789, AML#7915, AML#7919; Additional file 1: Figure S4).