ALDH2 and esophageal squamous cell carcinoma: Oral bacterial overgrowth is common in the stomachs of alcohol‐dependent patients.32 The overgrowth of oral bacteria in an achlorhydric stomach environment can explain the human experimental finding that ALDH2 deficiency and proton pump inhibitor (PPI) treatment markedly increased the acetaldehyde levels in the gastric juice after intragastric ethanol administration.33 The numbers of total gastroesophageal reflux and non‐acid reflux episodes were relatively high in ESCC patients.34 Among drinkers with CAG, the reflux of acetaldehyde‐rich gastric juice may increase the risk of ESCC.