Inhibition of KIT by dasatinib. Inhibition of the kinase activity of human wild-type (A,C) and mutant (B,D) c-KIT by dasatinib (A-B) and imatinib (C-D). Kinase activity was conducted on N-terminal GST-tagged recombinant c-KIT (amino acids 544-end). IC₅₀ was calculated by regression analysis.