FUT4 and B-cell chronic lymphocytic leukemia: Using an HLA-DRloCD11b+CD33+ phenotype to define MDSCs (Fig. S1) and expression of CD15 and CD14 to divide these into PMN-MDSCs and M-MDSCs subtypes (Fig. 1A and [24]), we found that the absolute numbers of MDSCs were significantly higher in 55 untreated CLL patients than 12 age-matched HCs (Fig. 1B).