The association with heavy smoking was evaluated assuming an additive genetic model using a per allele odds ratio (OR), which was determined using unconditional logistic regression in which a continuous variable for the number of minor alleles (0, 1, or 2) was entered into the regression model. The associated p-value is derived from the Wald chi-square with 1 degree of freedom. Linkage disequilibrium measurements (D' and r2) were made using Haploview v4.0.
