Currently, Imatinib is not the only TK inhibitor approved for patients with CML-CP (CML-Chronic Phase) including pediatric patients, but it remains the first-line therapy for patients with CML-AP (CML-Accellerate Phase) and CML-BC (CML-Blast Crisis). This evidence concerns the gene TKT and chronic myelogenous leukemia, BCR-ABL1 positive.