Subjects were of European descent, identified as smokers (defined as smoking 400 cigarettes lifetime), and had genotype data (N=5,216). Demographic descriptions are given in Table S1. These subjects smoked on average 23.6 cigarettes per day (CPD) (standard deviation=13.6) when smoking. Haplotype counts and frequencies in the ARIC sample were: GC (24.4%), GT (42.4%), and AC (33.2%), and they were labeled as H1, H2, and H3, respectively.
