PCSK9 and coronary artery disorder: In individuals with CHD, the PCSK9 gene expression and circulating blood protein levels are linked to promoter DNA methylation [20].IL-6 promoter hypomethylation, which results in its overexpression and systemic inflammation, has been linked to an increased risk of CHD [21].Atherosclerosis, the primary pathophysiology of CHD, is an inflammatory disease, as it is well documented [22].