The impaired methylation pathway, being a complex network of connections between the folates (such as folate and 5-methyltetrahydrofolate), one-carbon tetrahydrobipterin cycles, and the transsulfuration pathway, has been gaining interest with regard to CAD caused by genetic polymorphism of the methyltetrahydrofolate reductase gene (MTHFR). This evidence concerns the gene MTHFR and coronary artery disorder.