FHIT gene methylation usually occurs in the early stage of esophageal squamous-cell carcinoma and is significantly correlated with smoking, which can be used as a dormant biomarker for early esophageal squamous-cell carcinoma, greatly improving the diagnostic rate of esophageal squamous-cell carcinoma in the early stage of screening. This evidence concerns the gene FHIT and esophageal squamous cell carcinoma.