TGFB1 and neoplasm: Myeloid-derived suppressor cells (MDSCs) accumulate through the influence of various tumor-derived factors, such as vascular endothelial growth factor (VEGF), TGF-β, a variety of ILs, and prostaglandin E2 (PGE2), which inhibit the tumoricidal effect induced by tumor recognition by immune effector T lymphocytes and promote the survival of tumor cells [20,21].