Mouse Betacellulin is a single type I membrane protein which belongs to the EGF family of cytokines. EGF family has many members including EGF, TGF-a, Amphiregulin, HB-EGF, Epiregulin, Tomoregulin and the Neuregulins. Betacellulin is characterised by a six-cysteine consensus motif that forms three intra-molecular disulfide bonds crucial for binding the ErbB receptor family. Betacellulin is expressed in several tissues and tumor cells including kidney, uterus, liver, pancreas and small intestine. Betacellulin binds and activates ErbB-1 and ErbB-4 homodimers. Betacellulin is thought to play a role in the differentiation of pancreatic beta cells.Human and mouse mature BTC protein are 80% identical at the amino acid sequence level. Betacellulin is involved in many biological processes such as stimulating gastrointestinal growth. It is proteolytically processed from a larger membrane-anchored precursor and is a potent mitogen for a wide variety of cell types.