Influence of STI571 on the autophosphorylation of #ABL chimeras and the IC₅₀ for STI571 of Ba/F3 cells expressing the #ABL chimeras. (A) Autophosphorylation of p185^(BCR-ABL) and the different #ABL chimeras in the presence of increasing concentrations of STI571 detected by the relationship between the amount of ABL and phosphorylated ABL detected by α-ABL and α-pABL, respectively. (B) IC₅₀ for STI571 of Ba/F3 cells expressing p185^(BCR-ABL) and the different #ABL chimeras. Data presented are the mean of 2 independent experiments ± SD.