IL6 and neoplasm: Tumor cells secrete various immunosuppressive and anti-apoptotic factors (vascular endothelial growth factor (VEGF), TGF-β, IL-10 and IL-6, prostaglandine E2 (PGE2)) that create a tolerogenic microenvironment with accumulation of ICs harboring immunosuppressive phenotypes, such as myeloid-derived suppressor cells (MDSCs), tumor-associated macrophages (TAMs) and regulatory T-cells (Tregs).