Effect of NS-187 on in vitro growth of cell lines harboring Bcr-Abl. (A) Bcr-Abl–positive K562 cells, (B) Bcr-Abl–positive KU812 cells, (C) Bcr-Abl–negative U937 cells, (D) BaF3/wt cells, (E) BaF3/E255K cells, and (F) BaF3/T315I cells were treated with serial dilutions of NS-187 (•) or imatinib (○) for 3 days. Cell proliferation was assessed by means of the MTT assay.