MAPK1 and chronic myelogenous leukemia, BCR-ABL1 positive: It has been reported that CML CD34+ derived cells display basal Erk phosphorylation which is increased in the presence of IM [36], but several differences should be considered between our data and those from Chu et al. First, our data are obtained fundamentally by using cell lines derived from blast crisis, while in the report from Chu and co-workers the conclusions are obtained mainly from patients in chronic phase.