Results from the single SNP analyses are presented in Table 3 for EOT and 6-month follow-up, respectively. Only SNPs with an adjusted P-value <0.05 from a likelihood ratio test (LRT) and with stable effect estimates are presented in the tables. Results for all the SNPs are presented in Supplementary Material, Tables S1 and S2. Two SNPs within the 3′ UTR of the CHRNB2 (cholinergic receptor, nicotinic, beta 2) gene show a substantial impact on relapse at the EOT with an observed LRT P-value for the most significant SNP (rs2072661) of 9.97 × 10−4 and an adjusted P-value of 1.33 × 10−2. The two SNPs in CHRNB2 are in strong linkage disequilibrium (r2 = 0.96) with each other and their effect estimates following a similar trend with both SNPs demonstrating a dominant genetic model. For simplicity in presentation, we focus on reporting the result for rs2072661. Irrespective of treatment, having the minor allele for rs2072661, which was present in 23% of our subjects, decreases the odds of quitting substantially (OR = 0.40; 95% CI 0.25–0.67, P = 0.0004). The interaction effect
