Improved therapy regimen employing first-, second-, and third-generation tyrosine kinase inhibitors (TKI) directed at the abnormal BCR-ABL1 fusion tyrosine kinase (TK) lead to achievements of durable cytogenetic (CyR) and molecular remissions (MR) in patients with chronic myeloid leukemia (CML). This evidence concerns the gene TKT and chronic myelogenous leukemia, BCR-ABL1 positive.