One of the major risk factors for CAD is tobacco smoking which accounts for 10–15 % of the risk [2]. Recent studies have shown that smoking can interact with genetic variation to increase the risk of CAD [3, 4]. One of the potential mechanisms for this interaction is DNA methylation. DNA methylation is the attachment of a methyl group to a nucleotide which occurs most often at the cytosine nucleotide of CpG dinucleotides. Methylation has varying functions at different locations in the human genome including influence on gene expression [5].
