The ADH1C*1 allele also appears to have protective effects against alcoholism in Asian populations; however, this protection can be attributed to the fact that this allele usually is co-inherited with the protective ADH1B*2 allele and is not an independent effect of the ADH1C*1 allele (Chen et al. 1999a; Choi et al. 2005; Osier et al. 1999). This evidence concerns the gene ADH1B and alcohol dependence.