not yet clear (Furberg et al. 2010). To date, few GWAS studies of smoking cessation have been conducted (Uhl et al. 2007) in part due to the need for larger sample sizes than may be feasible to acquire from clinical trials. Below, we review genetic studies of the smoking cessation phenotypes with a focus on the role of genes encoding nAChR subunits and those implicated in nicotine metabolism.
