Endoglin also known as CD105 is a type I membrane glycoprotein located on cell surfaces and is part of the TGF-β receptor complex. It is involved in modulating a response to the binding of TGF-β1, TGF-β3, activin-A, BMP-2 and BMP-7. It has been postulated that Endoglin is involved in the cytoskeletal organization affecting cell morphology and migration. Endoglin has a role in the development of the cardiovascular system and in vascular remodeling. Its expression is regulated during heart development. Experimental mice without the Endoglin gene die due to cardiovascular abnormalities. In humans, Endoglin may be involved in the autosomal dominant disorder known as hereditary hemorrhagic telangiectasia (HHT) type 1. This condition leads to frequent nose bleeds, telangiectases on skin and mucosa and may cause arteriovenous malformations in different organs including brain, lung, and liver.