ANPEP and SHOX-related short stature: Other components of the renin-angiotensin system (RAS) may also play a role in the pathogenesis of ISS, such as aminopeptidase N (APN) which converts Ang III into angiotensin IV (Ang IV), reducing the levels of Ang III, the preferred endogenous agonist for the natriuretic Ang II type 2 receptor (AT2R), resulting in sodium retention and elevated BP [46,47].