CD8A and neoplasm: The PDAC TME harbors a large amount of immunosuppressive cell types, such as Tregs, M2-TAMs, and immature myeloid-derived suppressor cells (iMDSCs), which inhibit proper CD8+ T-cell responses, functional antigen presentation/lymphocyte activation by dendritic cells (DCs), or the anti-tumor response by M1 macrophages (M1-TAMs) [113].