Processing of angiotensin peptides by ACE, ACE2 and neprilysin as part of the rennin-angiotensin system. Renin cleaves angiotensinogen to produce angiotensin I. ACE converts angiotensin I to angiotensin II. In a second processing axis, angiotensin I is cut by ACE2 resulting in Ang [1–9], which is cleaved by either ACE or neprilysin (NEP) to produce Ang [1–7] (bracketed numbers refer to the amino acid positions within the peptide sequences). Ang [1–7] can also result from processing of angiotensin I by NEP or angiotensin II by ACE2. Binding of angiotensin II to the AT1 receptor activates vasoconstriction. In contrast, binding to the AT2 receptor mediates vasodilation, which can also be initiated by the binding of Ang [1–7] to the Mas receptor.