Further, the ablation of the pancreatic microbiome was associated with a reduction in the frequency of tumor-infiltrating immune cells with immunosuppressive tumorigenic myeloid-derived suppressor cells (MDSCs), along with an increase in anti-tumor M1 macrophage, Th1/CD4+T cells and CD8+T cells in the pancreatic tumor microenvironment. Here, CD8A is linked to pancreatic neoplasm.