Among the 28 imatinib resistant CML patients pre-treated with a non-TKI (HU), mutations were detected in only 7 patients whereas, 34 patients had mutations in the BCR/ABL gene among the 66 imatinib resistant patients with front-line imatinib. The gene discussed is BCR; the disease is chronic myelogenous leukemia, BCR-ABL1 positive.