ALDH2 and esophageal squamous cell carcinoma: Meta-analysis has shown that individuals with ALDH2*1/*2 have a 7.12- and 1.83-fold increased risk of ESCC [14] and HNSCC [27], respectively, compared with carriers of ALDH2*1/*1. Moreover, alcoholics with the ALDH2*1/*2 genotype have a 13.5- and 18.52-fold increased risk of ESCC and HNSCC, respectively, compared with ALDH2*1/*1 genotypes [15].