population. Recently, STOMP conducted a meta-analysis of smoking phenotypes (for example, number of cigarettes smoked per day and age of smoking initiation) in 32 389 African Americans (effective sample size ∼15 000).18 This well-powered meta-analysis produced one genetic variant of genome-wide significance (cholinergic receptor, nicotinic, alpha 5, CHRNA5 SNP rs2036527, P<5 × 10−8), several additional variants that were approaching significance (P<5 × 10−7) and many variants that fell short of statistical significance for the prediction of cigarettes smoked per day.
