Second-generation ABL TKIs such as nilotinib or dasatinib have been shown to induce major cytogenetic responses in approximately 50% of patients with imatinib-resistant or intolerant CML [4, 5] and are currently used clinically as first-line therapies for newly diagnosed CML [6, 7]. The gene discussed is ABL1; the disease is chronic myelogenous leukemia, BCR-ABL1 positive.