The cadherins are a family of Ca2+-dependent adhesion molecules that function to mediate cell-cell binding critical to the maintenance of structure and morphogenesis. Cadherins each contain a large extracellular domain at the N-terminus, which is characterized by a series of five homologous repeats, the most distal of which is thought to be responsible for binding specificity. Cadherin-20, also known as protocadherin gamma B4, is a member of the protocadherin gamma gene cluster. Expressed primariy in fibroblasts, cadherin-20 plays a critical role in neuronal cell-cell connections in the brain. Through its ability to mediate cell-cell adhesion, caderin-20 is thought to help the body respond to injury by regulating post-traumatic wound healing.