This study reports one of the first few GWAS of smoking behavior in Caucasians. Through this study, we identified a cluster of nine SNPs upstream from the IL15 gene, which ranked among the most significant 30 SNPs associated with smoking status in our GWAS (Appendix I). Gender-specific analyses indicated that these nine SNPs were associated with smoking status in a male-specific manner (Table 2). In particular, the SNP rs4956302 achieved a genome-wide significant p value of 8.80×10−8 in male subjects. Another SNP, rs17354547, is highly conserved across multiple species (Figure 2), suggesting its functional importance. Of note, these nine SNPs were also associated with another important phenotype for smoking behavior, cigarette consumption (SQ), and this association was also male specific (Table 2).
