The SIRT1 expression was lower in the tumor stage (I + II) than that in stage (III + IV) of ESCC (OR = 0.45, 95% CI: 0.32–0.63), and the difference was statistically significant (Z = 4.72, P < 0.05), (Figure 5). This evidence concerns the gene SIRT1 and esophageal squamous cell carcinoma.