Among the 1295 participants (6, 24), 1143 DNA samples were extracted from blood and genotyped (609 in Study 1 and 534 in Study 2). All four of the genotyped SNPs were in Hardy-Weinberg equilibrium (all P>0.05, Supplementary Table S1). Rs2036527 was selected for its role in influencing smoking behaviors in African Americans (21) while Rs16969968 (‘Bin A’), rs588765 (‘Bin B’), and rs578776 (‘Bin C’) were selected to represent three different haplotype bins which were previously associated with smoking behaviors (11). Rs2036527 had a minor allele frequency of 22.3%, Rs16969968 had a minor allele frequency of 5.7%, Rs588765 had a minor allele frequency of 31.7%, and Rs578776 had a minor allele frequency of 47.9%. These four SNPs were in low linkage disequilibrium (all r2 =0.02-0.39) suggesting that they were independent of each other (Supplementary Table S1). None of the four genotyped SNPs were significantly associated with baseline demographics, CPD, % smoking mentholated cigarettes, baseline plasma cotinine levels, baseline total nicotine equivalents levels, levels of nicotine dependence or treatment group assignment (Table 1 & Supplementary Table S2).
