ALDH2 and gastric cancer: Those with the genotype of ALDH2-2 allele or ADH1C*1/1, (genetic predisposition for alcohol-mediated cancer,) pose a higher risk for developing esophageal cancer [23,33,38,39] The variant ALDH2*2 allele is a genetic risk of smoke and alcohol-induced esophageal cancer (including esophageal squamous cell carcinoma), gastric cancer and pancreatic cancer [23,24,25].