IL10 and neoplasm: Conversely, lactate promotes M2-polarization of tumor-associated macrophages (TAMs) (17) and myeloid-derived suppressor cells (MDSCs), while stimulating their secretion of immunosuppressive mediators, such as vascular endothelial growth factor (VEGF), interleukin (IL)-10, and accelerating programmed death−ligand 1 (PD-L1) expression (18).