CD4 and pancreatic neoplasm: We then established orthotopic pancreatic tumor models in both healthy C57BL/6 mice (n = 8) and STZ-induced hyperglycemic mice (n = 8), and investigated their differences in the abundancy and function states of several subsets of immune cells, including CD4+ T cells, CD8+ T cells, macrophages, dendritic cells (DCs), and myeloid-derived suppressive cells (MDSCs).