The gene-based analyses revealed twenty-one genes significantly associated with smoking behaviours, including eight genes in the 15q25 region. Of the twenty-one genes, fifteen genes were not previously reported as significantly associated with any smoking or addiction phenotype in the GWAS catalogue (as of 2015-10-23, see www.genome.gov/gwastudies 28), and were not detected with the SNP-based approach in the original TAG analysis. One gene was associated with both quantity smoked and smoking cessation. Results are displayed in Table 1.
