the ARIC sample were not supported by biochemical confirmation. However, such confirmation was obtained in the UW-TTURC trial, and research shows that self-report is a valid indicant of current smoking, especially when there are no strong incentives to deceive (38). In addition, this work only studies one genetic locus and it is clear that multiple genes contribute to smoking cessation success. Future research should explore whether greater accuracy in predicting treatment response can be attained by the addition of other genetic variants implicated in differential treatment effects (39). Finally, this study only included subjects of European descent while the frequency and effects of these genetic variants differ by ancestry.
