PDCD1 and pancreatic neoplasm: The recent study indicated that the pancreatic cancer microbiome can promote oncogenesis by induction of innate and adaptive immune suppression, and bacterial ablation was associated with immunogenic reprogramming in pancreatic TME, with a reduction in myeloid-derived suppressor cells and an increase in M1 macrophage differentiation, leading to an efficacy for checkpoint-targeted immunotherapy by upregulating PD-1 expression [67].