In addition, the prognosis related DEOSGs were screened by univariate Cox and LASSO regression analysis, and a total of 11 DEOSGs: SERPINE1, CTLA4, HBB, F5, AGT, KIT, GPX3, GAD1, CYP19A1, BBC3, and NOX4 were identified with a good prognosis in patients with GC. The gene discussed is CYP19A1; the disease is gastric cancer.