Several SNPs in intron 1 were associated with drug addiction. In a study of 9 SNPs in Chinese subjects, heroin-induced positive response on first use was associated with SNPs rs534673 (originally called rs696522), rs1381376, and rs3778151 (Zhang et al. 2007). SNPs rs510769 and rs3778151 were found to be associated with heroin addiction in EA subjects, but not in AA subjects (Levran et al. 2008; Levran et al. 2009). SNP rs510769 was also associated with several effects of amphetamine (euphoria, stimulation and blood pressure) in healthy subjects of EA ancestry (Dlugos et al. 2011).
