The associations between the 15 CpG sites and mRNA expression of nearby CAD genes are shown in Additional file 1: Table S3. Increased methylation of cg05603985 (SKI) was associated with increased expression of cis-eQTL gene PRKCZ (estimate = 0.035, p = 1.4 × 10−4) (Additional file 1: Table S3 and Additional file 2: Figure S2). In the mediation analysis, we did not find a significant proportion of the association between tobacco smoking and expression of PRKCZ to be mediated by methylation of cg05603985 (proportion mediated = 0.24, p = 0.79). The other CpG sites were not associated with gene expression.
