Induction of factor-independent growth in Ba/F3 cells by the expression of the oligomerization interface-deficient ΔCCp185. (A) Ba/F3 cells were infected with a control vector, p185^(BCR-ABL) or ΔCCp185. Western blot analysis of expression levels and phosphorylation state was performed using the α-ABL and α-pY antibodies as indicated. (B) Factor-independent growth of Ba/F3 cells expressing the indicated transgenes. (C) Effect of 1 μM STI571 on IL-3–independent growth of Ba/F3 cells expressing p185^(BCR-ABL) or ΔCCp185 (mean of 3 independent experiments ± SD). (Left) Without STI571. (Right) With STI571.