CD14 and neoplasm: MDSCs contain myeloid progenitors cells and immature myeloid cells released from the bone marrow, which then could be differentiated into immunosuppressive cell subpopulations in response to tumour-secreted chemokines and cytokines, and can be further classified into CD11b+CD14−CD15+CD66b+LOX1+ PMN-MDSCs and CD14+CD15−HLA-DR−/low M-MDSCs (Gabrilovich and Nagaraj 2009).