A plethora of factors at tumor sites trigger different signaling pathways in MDSCs that lead to the development of immature monocytic myeloid-derived suppressor cells (M-MDSCs) Cd11b+Gr-1hiLy6Clo and polymorphonuclear myeloid-derived suppressor cells (PMN-MDSCs) Cd11b+Gr-1loLy6Chi. Here, ITGAM is linked to neoplasm.