ACE and aortic stenosis: Importantly, angiotensin-converting enzyme (ACE), angiotensin II (Ang II), and Ang II type 1 receptors (AT-1Rs) are expressed in the aortic valves and ACE activity is augmented in the stenotic valves [12,13], suggesting that inappropriate activation of the renin-angiotensin system (RAS) participates in the pathogenesis of AS.