tissue-specific nature of CHRNA5 RNA expression. For example, we observed that the genetic effects on CHRNA5 total mRNA expression in lymphoblastoid cells of European ancestry are in the opposite direction to that observed in human brains. Studies with promoter haplotypes, including rs3841324 and/or rs503464 within the CHRNA5 promoter region and rs55853698 and rs55781567 within the 5′UTR, have shown that CHRNA5 transcriptional activity was modulated by the promoter haplotype [21], [25]. It is possible that CHRNA5 transcription is affected by variants in the 5′UTR, and adjacent and the 5′distal region of the CHRNA5 promoter.
