In immunologically cold tumors, such as PDAC, the TME is also spiked with a large number of immunosuppressive regulatory T-cells (Tregs), M2-polarized tumor-associated macrophages (TAMs) and immature myeloid-derived suppressor cells (iMDSCs), which inhibit functional CD8+ T-cell responses and impede proper antigen presentation by DCs or anti-tumor responses by M1-polarized macrophages [163]. Here, CD8A is linked to neoplasm.