CSF1 and neoplasm: Colony stimulating factor 1 (CSF-1) is another immunosuppressive cytokine present in the TME that mediates its suppressive effect by recruiting suppressive myeloid cells and promoting macrophage differentiation toward an M2 phenotype and preclinical studies suggest targeting its receptor, CSF-1 receptor, may be an effective way to increase T cell infiltration and improve the ability of T cell-based therapies to control tumor growth in solid tumors [175,176].