In addition, univariate Cox analysis was performed to identify the protective factors for ESCC: 10 protective factors (MAOA, INMT, ALDH7A1, AOX1, AKR1A1, ALDH9A1, ACAT1, HAAO, ALDH2, and HADH) were identified in the GSE121931 cohort (Figure 5C). This evidence concerns the gene HADH and esophageal squamous cell carcinoma.