An immunosuppressive and pro-tumorigenic phenotype observed in the PDAC tumor microenvironment is attributed to the imbalance in the number of immune cells, such as immunosuppressive T regulatory cells (Treg), M2 polarized tumor-associated macrophages, and myeloid-derived suppressor cells (MDSCs) that prevail over cytotoxic CD8 T cells, and dendritic cells. The gene discussed is CD8A; the disease is neoplasm.