In addition to tumor-associated macrophages (TAM), intratumoral administration of exogenous GM-CSF also resulted in increased ratio of monocytic (M-MDSC, CD11b+Gr1+Ly6G-Ly6Chigh) over polymorphonuclear (PMN-MDSC, CD11b+Gr1+Ly6G+Ly6Clow) myeloid-derived suppressor cells (Fig 4E–4F). The gene discussed is CSF2; the disease is neoplasm.