Regulates ADAM17 protease, a sheddase of the epidermal growth factor (EGF) receptor ligands and TNF, thereby plays a role in sleep, cell survival, proliferation, migration and inflammation. Does not exhibit any protease activity on its own. Homodimer, or homooligomer. Interacts with TGFA and HBEGF (PubMed:15965977). Interacts with EGF; may retain EGF in the endoplasmic reticulum and regulates its degradation through the endoplasmic reticulum-associated degradation (ERAD) (PubMed:21439629). Interacts (via cytoplasmic N-terminus) with FRMD8/iTAP; this interaction leads to mutual protein stabilization (PubMed:29897333, PubMed:29897336). Interacts with ADAM17/TACE (PubMed:29897333). Predominantly localized in the endoplasmic reticulum membrane (PubMed:15965977). Highly expressed in cerebellum, cerebrum, heart, skeletal muscle, placenta, pancreatic islet and testis. Detected at lower levels in colon, kidney, small intestine and lung. N-glycosylated. Belongs to the peptidase S54 family. Truncated N-terminus.