GCN1 Expression in Hepatocellular Carcinoma Tissues Versus Normal Tissues and Its Diagnostic Efficacy. A. GCN1 gene expression levels in the TCGA-LIHC cohort show significantly higher expression in tumor tissues compared to normal tissues (P < 0.001). B. In paired samples from the TCGA-LIHC cohort, tumor tissues also exhibited significantly higher GCN1 expression than adjacent non-tumorous tissues (P < 0.001). C. The ROC curve evaluated the ability of GCN1 to distinguish tumor tissues from normal tissues in the TCGA-LIHC cohort.