We found IL18RAP, CTLA4, SLC2A3, IL1A, KRT7, PEG10, IGFBP2, GPA33, and DES are key genes of gastric cancer and deeply explored the potential role in clinicopathological features, immune infiltration, TME and prognosis in GC, providing new immunotherapy strategies and drug targets for the clinical treatment of GC patients. The gene discussed is PEG10; the disease is gastric cancer.