Establishment of imatinib selectivity. (A) Imatinib (CGP57148) at a concentration of 10 μM does not inhibit the growth of 32D cells (32D + IL-3, ○; 32D + IL-3 + imatinib, ▵). (B) Imatinib at 1 μM inhibits the growth of 32D cells expressing BCR-ABL (32Dp210); the effect is partially reversible with IL-3 (32Dp210 alone, ▴; + imatinib, ○; + imatinib + IL-3, □). (C) Imatinib does not affect the growth of 32D cells transformed by SRC (32Dv-SRC alone, □; + 10 μM imatinib, ○). Reproduced from Druker et al¹⁸  with permission from Nature, copyright 1996. O.D. indicates optical density. Error bars indicate mean ± standard deviation.