2001; Yokoyama et al., 1999; 2003), we expected the effects of ADH1B on alcohol sensitivity might be stronger in individuals who also possess an ALDH2*2 allele. These findings would support the step of the hypothesized pathway that proposes an association between ADH1B variations and responses to alcohol, and would contribute some validity and clarity to the proposed mechanism of action for how these variants lead to protection against the development of AUDs.