Inhibition of autophosphorylation of FLT3 and phosphorylation of STAT5 in mutant FLT3–expressing cells. (A) IP/Western: treatment of FLT3-ITD-Ba/F3 cells for 15 minutes with NVP-AST487 at 0.01 μM. A vertical line has been inserted to indicate a repositioned gel lane. (B) IP/Western: treatment of FLT3-N841I-Ba/F3 cells for 15 minutes with 0.01 or 0.1 μM NVP-AST487. (C) Immunoblot: treatment of FLT3-ITD-Ba/F3 cells for 2 hours with NVP-AST487 at 0 to 1000 nM. (D) Immunoblot: treatment of FLT3-ITD-Ba/F3 cells for 2 hours with PKC412 at 0 to 1000 nM.