Using the TCGA database, we confirmed that both CXCR2 and CXCL8 are overexpressed in ESCC (Figure S5A), whereas CXCL8 exhibited a high diagnostic value for esophageal cancer (Figure S5B; AUC: 0.95, 95% CI: 0.893–1.000). This evidence concerns the gene CXCL8 and esophageal squamous cell carcinoma.