ADH1B R48H allele (also known as ADH1B*1) was protective against UADT cancer, whereas three ALDH2 variants were associated with an increased risk of alcohol-related UADT cancers. It should be noted, however, that, unlike the ADH1B R48H and the Asian ALDH2 G487K alleles, both of which encode enzymes with alter activity, the functional significance of these other ALDH2 variants, if any, remains to be determined.
