ACE, a key component of the RAS, is a peptidase that cleaves the histidyl-leucine dipeptide from inactive angiotensin I. It is well documented that angiotensin-converting enzyme (ACE, EC 3.4.15.1) gene polymorphisms are associated with various diseases such as hypertension, coronary artery disease, myocardial infarction and diabetes [3]. The gene discussed is ACE; the disease is diabetes mellitus.