A DHODH inhibitor (IC50 = ~20 nM); selective for DHODH over a panel of greater than 400 kinases at 100 nM; induces differentiation of ER-HoxA9, U937, and THP-1 cells in vitro (ED50s = ~1 μM); induces differentiation of tumor cells and reduces tumor growth in a THP-1 mouse xenograft model at 15 mg/kg three times daily or 5 mg/kg per day; induces differentiation of bone marrow leukemic cells and increases survival In a retroviral transduction mouse model of HoxA9 + Meis1 AML