Within the tumor microenvironment, COX-2, prostaglandins, SCF, CCL2, GM-CSF, M-CSF, VEGF, CXCL5, calcium-binding pro-inflammatory proteins S100A8 and S100A9, and TNF, all favor the chemotaxis and expansion of immunosuppressive MDSCs [151]. Here, KITLG is linked to neoplasm.