Ecto-5'nucleotidase (NT5E, also called CD73) is a 70 kDa glycosyl phosphatidylinositol-anchored membrane-bound glycoprotein that catalyzes the hydrolysis of extracellular nucleoside monophosphates into bioactive nucleoside (1). NT5E catalyzes the terminal step of extracellular adenosine formation from adenosine-monophosphate, therefore driving the regulation of extracellular adenosine levels and the downstream activation of the four G protein-coupled adenosine receptors (2). Binding of hypoxia-inducible factor (HIF-1) to the NT5E gene promotor leads to upregulation of NT5E during hypoxia (3). NT5E biological roles span from lymphocyte adhesion (4,5), to fibrosis (6), to regulation of nociception (7,8).
