AKR1A1 and cancer: Indeed, gene polymorphisms in aldehyde and alcohol dehydrogenase enzymes (ALDH2 and ADH, respectively), which are linked to an increased acetaldehyde exposure, substantially enhance cancer risk in alcohol drinkers, and these phenomena “...provide undisputable evidencefor acetaldehyde being a local carcinogen not only in oesophageal but also ingastric cancer.