Fig. 1
![Fig. 1](http://media.springernature.com/full/springer-static/image/art%3A10.1186%2Fs41021-015-0020-x/MediaObjects/41021_2015_20_Fig1_HTML.gif)
CHRNA5 mRNA expression in the putamen compared across rs7164030 genotypes, as measured by qPCR. Samples homozygous for the major “A” allele (A/A) of rs7164030 have approximately 3.5-fold less CHRNA5 mRNA versus samples homozygous for the minor “G” allele, with heterozygotes exhibiting intermediate levels (ANOVA p=1.82×10−6)