Ephrin receptors and their ligands, the ephrins, mediate numerous developmental processes, particularly in the nervous system. The Eph family of receptors are divided into 2 groups based on the similarity of their extracellular domain sequences and their affinities for binding ephrin-A and ephrin-B ligands. Ephrin type-B receptor 2 is a receptor for members of the ephrin-B family and it acts as a tumor suppressor. It is a single-pass type I membrane protein that is expressed in brain, heart, lung, kidney, placenta, pancreas, liver and skeletal muscle. It is preferentially expressedd in fetal brain. Defects in this protein are involved in the development of prostate cancer metastasis to the brain.