Data on self-reported smoking status (never smoker, former smoker, and current smoker), genotype (rs16969968 or rs1051730), and cotinine levels determined in blood (plasma or serum), as well as cigarette consumption (cigarettes per day) among current smokers, were available from participants of self-reported European ancestry in six independent studies (British Regional Heart Study [BRHS], n = 385 subjects; British Women’s Heart and Health Study [BWHHS], n = 400 subjects; European Prospective Investigation into Cancer and Nutrition [EPIC], n = 759 subjects; Midspan, n = 499 subjects; Patch II, n = 451 subjects; Patch in Practice [PiP], n = 438 subjects) that contributed to this analysis (2,29–40). All studies received appropriate ethics approval, and informed consent was obtained from each participant. These studies are described in detail in Supplementary Methods (available online).
