approaching significanceP <5 × 10 −7
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.