Given this background, the aim of the present study was to assess the possible association between, angiotensin-converting enzyme insertion/deletion (ACE I/D), angiotensin receptor II (Ang II AT2-C3123A) and angiotensinogen (AGT-M235T) in Saudi patients with coronary artery disease as confirmed by coronary angiography diagnosis, because the contribution of these RAS polymorphisms to the pathogenesis of CAD has not been studied previously in Saudi CAD patients. Here, ACE is linked to coronary artery disorder.