FLT3 and acute lymphoblastic leukemia: In t(4;11) pro-B-ALL context, the exposure of SEM-K2 cells to GSK126 and EPZ6438 resulted in increased expression of FLT3 (Supplementary Fig. S4B) and its downstream signaling, mediated by STAT5 phosphorylation (Supplementary Figs. S4C and S4D).