ERBB4, which binds to several items including betacellulin, is part of the epidermal growth factor receptor family, deficiencies in which are associated with Alzheimer's and MS.
The protein binds to and is activated by neuregulins-2 and -3, heparin-binding EGF-like growth factor and betacellulin. Receptor tyrosine-protein kinase erbB-4 is a receptor tyrosine kinase that is a member of the epidermal growth factor receptor family. The ErbB family of proteins contains four receptor tyrosine kinases, structurally related to the epidermal growth factor receptor (EGFR), its first discovered member. Insufficient ErbB signaling in humans is associated with the development of neurodegenerative diseases, such as multiple sclerosis and Alzheimer's Disease, while excessive ErbB signaling is associated with the development of a wide variety of types of solid tumor. Multiple sclerosis (MS), also known as encephalomyelitis disseminata, is a demyelinating disease in which the insulating covers of nerve cells in the brain and spinal cord are damaged. 
