CD8A and neoplasm: Various cell types, including MDSCs, macrophages, TH17 cells and other CD8+ T cells, are present in the TME of Kras-mutant PDAC mice during the early stage of pancreatic carcinogenesis.98 In particular, peripancreatic leukocytes can either be protective against carcinogenesis by restraining tumor growth via antigen-restricted tumoricidal immune responses or, conversely, promote tumor progression through the induction of immunosuppression.403T cells.