Although this mechanism is also unclear, we speculate that this association might be affected by alcohol dependence.33 Individuals who are heterozygous or homozygous for the Lys allele of ALDH2 Glu504Lys polymorphism (rs671) have greatly reduced ability to metabolize acetaldehyde, which greatly decreases their risk for alcohol dependence.34 After definitive treatment, ALDH2 Glu/Glu patients might maintain higher levels of alcohol consumption than ALDH2 Glu/Lys patients. This evidence concerns the gene ALDH2 and alcohol dependence.