Overall, these data indicate that the ENU-based assay faithfully reproduces the spectrum of mutations seen in patients with clinical resistance to imatinib mesylate...Spectrum and frequency of BCR-ABL kinase domain mutations recovered in the presence of imatinib mesylate, nilotinib, and dasatinib...Although both dasatinib and nilotinib are much more potent than imatinib mesylate and have activity against most kinase domain mutants, it is conceivable that their specific modes of binding to Abl may lead to new “vulnerable” sites that could confer drug resistance.