NOX4 and gastric cancer: The expression patterns of these 11 DEOSGs on mRNA and protein levels using TCGA expression data and HPA database revealed that SERPINE1, CTLA4, F5, AGT, GAD1, CYP19A1, BBC3, and NOX4 were overexpressed, while HBB, KIT, and GPX3 were downregulated in GC tissues.