In line with preclinical findings, genetic studies have reported that gain-of-function mutations in the PCSK9 gene cause autosomal dominant hypercholesterolemia [88], while loss-of-function mutations in the PCSK9 gene are closely associated with low LDL-C levels and reduced risk of coronary heart disease (CHD) [89,90]. This evidence concerns the gene PCSK9 and coronary artery disorder.