These catalytic inhibitors were shown to elicit potent antileukemic effects in vitro [80, 81] and in vivo [81] on CML or Ph+ ALL cells, including cells expressing the T315I BCR-ABL mutation, which is resistant to the kinase inhibitors currently approved for use in the treatment of CML and Ph+ ALL (imatinib mesylate, nilotinib, dasatinib). The gene discussed is ABL1; the disease is acute lymphoblastic leukemia.