Strong evidence exists to show that the heterozygous genotype (ALDH2*1/*2) contributes substantially to the development of oesophageal cancer related to alcohol consumption, with up to a 12 fold increase in risk seen in heavy drinkers when compared to carriers of the homozygous ALDH2*1/*1 genotype (which encodes the active enzyme) [12,13]. Here, ALDH2 is linked to carcinoma of esophagus.