CEP-701–mediated inhibition of FLT3 activity inhibits phosphorylation of STAT5 and ERK1/2.

Cells were incubated with increasing concentrations of CEP-701 prior to lysis as in Figure 1. For STAT5, 500 μg protein extract was immunoprecipitated with anti-STAT5 antibody followed by immunoblotting with antiphosphotyrosine antibody 4G10. For ERK1/2, 50 μg protein extract was loaded per lane and immunoblotting was performed with antiphospho-ERK antibody. Equal protein loading was confirmed (not shown) by stripping the blots and reprobing with anti-STAT5 and anti-ERK antibodies, respectively.