When the MDSCs in peripheral blood mononuclear cells (PBMCs) of lung cancer patients were analyzed for CD14 expression, we noticed a significant increase in the concentration of CD11b+CD33+HLA-DR–CD14+ (M-MDSCs) and CD11b+CD33+HLA-DR–CD14– (G-MDSCs) compared with healthy donors and lung hamartoma patients (Figure 1A, 1B). Here, CD33 is linked to lung cancer.