Imatinib (IM) is the frontline therapy for CML patients, achieving an high rate of Major Molecular Response (MMR; defined as 3-log reduction in BCR/ABL transcript level from a standardized baseline value) and Complete Molecular Response (CMR; defined as at least 4-log reduction corresponding to undetectable BCR/ABL transcript by real-time reverse transcription polymerase chain reaction) [6, 7] which might represent an ‘operational cure’ as well as a pre-requisite for IM discontinuation [8]. The gene discussed is ABL1; the disease is chronic myelogenous leukemia, BCR-ABL1 positive.