Imatinib (Gleevec, STI571), one of the BCR-ABL tyrosine kinase inhibitors (TKIs), has been recommended as the first-line treatment for CML, which competitively inhibits the binding of adenosine triphosphate (ATP) to BCR-ABL kinase domain and blocks the substrate phosphorylation of BCR-ABL [5]. The gene discussed is ABL1; the disease is chronic myelogenous leukemia, BCR-ABL1 positive.