Growth of BaF3 FLT3/ITD resistance mutants in the presence of FLT3 tyrosine kinase inhibitors. Resistance was confirmed by performing site-directed mutagenesis of FLT3/ITD and nucleoporation in BaF3 cells. The resulting clones were grown in the absence of interleukin-3 and analyzed by treatment in increasing concentrations of FLT3 TKI for 2 days, after which growth inhibition was assessed using the MTT assay. Means are representative of at least three independent experiments. Cells expressing FLT3 resistance mutations were treated with (a) Lestaurtinib, (b) Midostaurin, (c) KW2449, (d) Sorafenib, (e) Sunitinib, (f) AGS324 or (g) AC220.