Obeidat M, et al. - Researchers investigated genetic variants associated with quantitative smoking and cessation in individuals with mild to moderate chronic obstructive pulmonary disease (COPD), using data from the Lung Health Study (LHS; a longitudinal multicenter study of mild-to-moderate COPD subjects who were all smokers at recruitment). Genome-wide association studies (GWAS) analyses, adjusted for age, gender, and genetic principal components, were performed. Significant associations with lung function were only shown by the CHRNA3/5 locus but this was observed only in heavy smokers. Overall, the genetic contribution to multiple aspects of smoking behaviour can be more precisely captured using objective measures of smoking such as exhaled carbon monoxide and/or salivary cotinine. The KCNMA1 gene association with smoking cessation was also noted, which may represent a potential therapeutic target.