Although we had genotyping data available for other SNPs in these samples, in this study, we focused only on the CHRNA5/A3/B4 region of chromosome 15, as this region has received much attention for its association with smoking and LC [14], [15], [16], [17], [24]. According to the genomic locations, 36 SNPs were selected. Of them, 32 met our inclusion criteria for this study with a satisfying Hardy-Weinberg equilibrium P value >10−6, MAF >0.01, and genotype call rates >95%. The 36 SNPs are described in Table 1.
