Ephrin-B1 is a member of the ephrin family. The encoded protein is a type I membrane protein and a ligand of Eph-related receptor tyrosine kinases. It may play a role in cell adhesion and function in the development or maintenance of the nervous system.Disruption of EphB2 and EphB3 genes revealed that their gene products restrict cell intermingling and allocate cell populations within the intestinal epithelium. In EphB2/EphB3 null mice, the proliferative and differentiated populations intermingled. In adult EphB3 -/- mice, Paneth cells did not follow their downward migratory path, but scattered along crypt and villus. The authors concluded that, in the intestinal epithelium, beta-catenin and TCF couple proliferation and differentiation to the sorting of cell populations through the EphB/ephrin B system.