ALDH2 and esophageal squamous cell carcinoma: As shown in Figure S1, in the allelic model, we found that the variant rs1229984 of ADH1B increased the risk of ESCC (OR: 1.50; 95% CI: 1.21–1.87), but ALDH2 rs671 was not associated with ESCC risk significantly (OR: 1.33; 95% CI: 0.92–1.92).