Plasma from AZD0530-treated subjects does not inhibit Abl signaling to Stat5. (A) The level of pStat5 and total Stat5 in K-562 cells incubated with the indicated concentrations of AZD0530 or STI-571 is shown. (B) The pStat5 level from experiments in (A) was measured by microdensitometry and a half maximal inhibitory concentration (IC50) determined for each compound. (C) The plasma inhibitory activity for Abl was detected by pStat5 level in K-562 cells incubated with plasma from subjects treated with the indicated doses of AZD0530. (D) The plasma Abl inhibitory activity determined by pStat5 level was measured in all subjects, and is plotted as mean ± standard error of the mean. No significant difference between groups was observed (n.s.).