Imatinib induces durable cytogenetic and molecular remission and prolonged lifespan in the majority of patients with CML [5], but approximately 20–30% of the patients eventually experience drug resistance, mainly as a consequence of mutations in the BCR/ABL kinase domain, genomic amplification of nonmutated BCR/ABL and BCR/ABL independence pathway [5–8]. The gene discussed is ABL1; the disease is chronic myelogenous leukemia, BCR-ABL1 positive.