ADH1A and gastric cancer: Although the exact role of ethanol consumption in the development of gastric cancer is poorly understood and remains to be elucidated, it has been demonstrated that genetic variants in the ADH1 gene may decrease its function or activity, and the less-active ADH1 might lead to a decreased elimination rate of ethanol and result in prolonged exposure to microbially derived carcinogenic acetaldehyde, which may play an essential role in the pathogenesis of gastric cancer [12], [41].