and additional SNPs that form a common FKBP5 haplotype, have been reported to be associated to the presence of a number of different psychiatric traits in EAs and AAs.11-14, 37 We confirmed our expectations regarding linkage disequilibrium with a post-hoc examination of rs1360780 in the laboratory sample; as expected the linkage disequilibrium (determined with Haploview54) for rs3800373 and rs1360780 was high (r2 > 0.9 and D’ > 0.95). Given the LD structure of the gene, a much larger sample will be required to clearly distinguish the independent effects of FKBP5 SNPs (and other variants). The FKBP5 mRNA findings were independent of genotype in our statistical models, but the power to detect interactive or moderating effects of genotype may have been limited by the modest sample size. Alternatively, cell specificity could favor the detection of FKBP5 SNP effects on gene expression in cells from tissues, such as brain, that are more relevant to the behavioral effects of stress, nicotine and nicotine withdrawal. It is interesting that FKBP5 genotype and mRNA are both associated with the “negative” effects domain of the DEQ. Each effect is interactive with nicotine dose, but, as noted above, the effect profiles differ. This may indicate that FKBP5
