As nearly 540 million people of either sex carry the ALDH2*2 genetic variant, the frequency of ALDH2*2 carriers within the human population shines an initial light into understanding how alcohol use, an inactive ALDH2 genetic variant, and subsequent acetaldehyde-induced ROS production can lead to an increased risk for aerodigestive tract and esophageal cancers [12, 18–22]. The gene discussed is ALDH2; the disease is esophageal cancer.