In summary, this study has not only comprehensively analyzed the characteristics of purine metabolism in the pancreatic-cancer microenvironment but also delved deeply into the impacts of abnormal purine metabolism on cell differentiation, interaction, and the efficacy of immunotherapy, and identified key representative genes GMPS and NT5E, particularly clarifying the intermediate-mediating role of NT5E in the purine-metabolic reprogramming of the pancreatic-cancer TME and the formation of an immunosuppressive environment. This evidence concerns the gene GMPS and pancreatic neoplasm.