In CML, Notch signalling has been demonstrated to mediate the disease progression [12] and in K562 CML cell line model Notch signalling inhibited the development of erythroid/megakaryocytic cells by induction of Hes1 [13] and proliferation of K562 cells [14]. This evidence concerns the gene HES1 and chronic myelogenous leukemia, BCR-ABL1 positive.