Macrophages are thought to serve a major function in the induction of immunosuppression in PDAC; IL-10+Arg1+MHCIIlo tumor-associated macrophages (TAMs) are predominant in the PDAC TME, and are effective in promoting Th2 cell differentiation, but ineffective in inducing CD8+ T-cell immunity (253–257). This evidence concerns the gene CD8A and neoplasm.