CD8A and neoplasm: M2 can produce cytokines, such as TGF-β, vascular endothelial growth factor (VEGF), IL-6, IL-10, and prostaglandin E2 (PGE2), and chemokines that promote angiogenesis or destruct the extracellular matrix, thereby helping tumor cells to invade and metastasize and they can stimulate Treg development and expansion while suppressing CD8+ T cell function (72, 73).