ARG1 and chronic myelogenous leukemia, BCR-ABL1 positive: Evaluating Arg1 expression and activity in 8 patients at diagnosis, the protein levels resulted significantly higher in CML PMNs in respect to autologous Gr-MDSCs (p<0.001; fig.4A) so as enzymatic activity (47,2±15,3 U/L in CML Gr-MDSCs vs 81,8±19,9 U/L in CML PMNs; p<0.001) (fig.4B).