FUT4 and cancer: Therefore, to visualize minor and potentially unique cell subpopulations within G-MDSCs, we next performed mass cytometry (CyTOF) of PBMCs, gating on CD15+ cells (LDGs), comparing healthy controls, patients with MBC, patients with Gram-positive sepsis, and patients with malignant melanoma, as an example of another cancer type (Fig 3A and B).