CD8A and neoplasm: Furthermore, functioning as immunosuppressive cells, TAMs produce a variety of immunoregulatory cytokines such as TGFβ, IL-10, and prostaglandin E2 (PGE2) and express inhibitory molecules PD-L1 and PD-L2, which promote Treg cell infiltration and inhibit anti-tumor CD8 T cell activity (44, 45).