It is important to note that ALDH2 deficiency does not influence esophageal cancer risk in non-drinkers [11]. Furthermore, the magnitude of the ALDH2-associated esophageal cancer risk depends on the relative importance of alcohol versus other risk factors in a given population. In rural areas of China, where there is a high rate of esophageal cancer but alcohol drinking plays a less important role than in Japan and Taiwan, there is a more modest positive association (ORs, 1.7 to 3.1) between low-activity ALDH2 heterozygotes and esophageal cancer risk (e.g., [16]).
