rs1051730 is a risk SNP for the interlinked phenotypes of lung cancer, smoking behavior and nicotine dependence37-42. It is a synonymous exonic SNP located in CHRNA3 in a region of high linkage disequilibrium that covers the related genes CHRNA5 and CHRNB4. In our data it is a significant gene-level and exon-level cis-eQTL for CHRNA5 alone (P = 5.11 × 10−6 for expression ID 3603447 in occipital cortex; P = 4.10 × 10−10 for expression ID t3603436 in average-all; Fig. 7c), a finding that potentially clarifies the mechanism of action of this well-established locus.
