The evidence for a role of the CHRNA5/B4/A3 cluster for the five phenotypes is presented in Table 3. Several different SNPs predicted the risk to initiate substance use. Note that with a single exception all p values <0.1 were observed for risk of onset within the user class. All SNP effects predicting differences between subjects with and without reported first use had p values >0.1 with the exception of rs1948 which had a p value of .037 in the 2-class proportional hazard model for other substances.
