Effect of tyrosine-kinase inhibitors on phosphorylation of STAT5 and RPS6 in TKI-sensitive and -resistant cell lines. Cell lines JURL-MK2 and SUP-B15 were treated for 3 h with imatinib or nilotinib. Phosphorylation of STAT5 and RPS6 was determined by Western blot analysis using the appropriate antibodies. Note that imatinib and nilotinib inhibited STAT5 phosphorylation (as shown by loss of pSTAT5) in TKI-sensitive and -resistant cell lines. GAPDH was used as loading control.