ALDH2 and colorectal cancer: Yang's study [17] found that the ALDH2 A/A genotype could increase susceptibility to CRC (adjusted OR = 1.86 (95% CI, 1.12–3.09)); however, Yin's study [19] discovered that the ALDH2A/A genotype was related to a statistically significantly decreased risk of colorectal cancer (adjusted OR 0.55, 95% CI  =  0.33–0.93).