The advantages of this study include the detailed phenotype profiles, allowing us to more precisely handle the complexity of the smoking behavior phenotype, which has previously been modeled in a relatively static way (e.g., ever vs. never smoker). This approach to phenotype refinement may help to identify novel signals, and perhaps be tractable with smaller samples than conventionally required. Our novel results suggest that the various stages in smoking history are affected by different underpinning mechanisms. Complex neurotransmitter networks including dopamine and glutamate may play a critical role in initiation, while airway inflammation possibly contributes to smoking cessation.
