FLT3-IN-14 is a potent FLT3 inhibitor with IC 50 s of 5.6 nM and 1.4 nM for FLT3-WT and FLT3-ITD. FLT3-IN-14 reduces the phosphorylation of FLT3 (Y591), induces cell cycle arrest at G1 phase and apoptosis. FLT3-IN-14 significantly reduces the tumor growth in an MV4-11 xenograft mouse model.