Multiple original studies, reviews and meta-analyses and from Asia also found that the mutation of ALDH2*2 and the deficiency of ALDH2 enzyme activity were commonly implicated in UADT cancers due to the increased DNA damage induced by acetaldehyde cancers (Matsuda et al., 2006; Asakage et al., 2007; Yang et al., 2007; Hiyama et al., 2008; Ding et al., 2009; Lee et al., 2009; Cadoni et al., 2012). This evidence concerns the gene ALDH2 and cancer.