It is very important in the [[Renin Angiotensin Aldosterone System|Renin Angiotensin Aldosterone System (RAAS)]]. ACE is predominantly expressed on epithelial cell membranes in the pulmonary ciculation and this is therefore, the site of action of the ACE inhibitor drugs. | It is very important in the [[Renin Angiotensin Aldosterone System|Renin Angiotensin Aldosterone System (RAAS)]]. ACE is predominantly expressed on epithelial cell membranes in the pulmonary ciculation and this is therefore, the site of action of the ACE inhibitor drugs. |