in both studies, including the nonsynonymous α5 rs16969968 SNP, even with the substantial difference in FTND criteria. Using similar criteria for low and high dependence as our study, a previous study [7] also reported a suggestive association (primary P = 0.08) of the CHRNA5-A3-B4 cluster in a small sample population of 242 Israeli women. A recent follow-up candidate gene analysis using genome-wide association data from three European populations data suggested a risk effect of CHRNA5-A3-B4 locus for cigarettes per day regularly smoked [32].
