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. The signaling pathway downstream of the receptor is referred to as forward signaling while the signaling pathway downstream of the ephrin ligand is referred to as reverse signaling (By similarity). Interacts with EPHA8; activates EPHA8. Expressed in brain, skeletal muscle, spleen, thymus, prostate, testis, ovary, small intestine, and peripheral blood leukocytes. Belongs to the ephrin family.