Cell surface GPI-bound ligand for Eph receptors, a family of receptor tyrosine kinases which are crucial for migration, repulsion and adhesion during neuronal, vascular and epithelial development. Binds promiscuously Eph receptors residing on adjacent cells, leading to contact-dependent bidirectional signaling into neighboring cells. May play a role in the interaction between activated B-lymphocytes and dendritic cells in tonsils (By similarity). Expressed in myogenic progenitor cells. In myogenic progenitor cells, highly expressed at 11.5 dpc and ceases its expression at the late fetal stage (17.5 dpc). Belongs to the ephrin family.