PSMC4 and gastric cancer: Utilizing TCGA dataset and the GTEx database, our comprehensive analysis of PSMC4 mRNA expression across 33 cancer types and their corresponding normal tissues revealed significant upregulation of PSMC4 in 26 out of these 33 types, most notably in hepatocellular carcinoma, lung adenocarcinoma, squamous cell carcinoma of the lung, and gastric cancer (Figure 1A).