While + 8 and i(17q) copy number abnormalities are frequently found in CML patients [19] and, according to the WHO 2016 criteria, are “major route” abnormalities that define accelerated phase (AP) if found in BCR::ABL1+ cells at diagnosis [20], del(18p) is rarely detected. This evidence concerns the gene ABL1 and chronic myelogenous leukemia, BCR-ABL1 positive.