ADAM17(ADAM metallopeptidase domain 17), also called TACE (tumor necrosis factor-alpha-converting enzyme), is a 70-kDa enzyme that belongs to the ADAM protein family of disintegrins and metalloproteases. Expression studies showed that the encoded protein cleaves precursor tumor necrosis factor-alpha to its mature form. Northern blot analysis revealed that the gene was expressed as a 5-kb mRNA in all tissues examined. ADAM17 is understood to be involved in the processing of tumor necrosis factor alpha (TNF-alpha) at the surface of the cell, and from within theintracellular membranes of the trans-Golgi network. This process, which is also known as 'shedding', involves the cleavage and release of a soluble ectodomain from membrane-bound pro-proteins (such as pro-TNF-alpha), and is of known physiological importance. ADAM17 was the first 'sheddase' to be identified, and is also understood to play a role in the release of a diverse variety of membrane-anchored cytokines, cell adhesion molecules,receptors, ligands, and enzymes.