Moreover, restoration of p16 (INKa) or p14 (ARF) into Ph-positive leukemic cells (both CML in blast crisis and ALL) is able to determine cell growth arrest and/or apoptosis suggesting a pathogenic role for these deletions and their co-operating role with BCR-ABL [39]. This evidence concerns the gene CDKN2A and chronic myelogenous leukemia, BCR-ABL1 positive.