Ephrin-A1 (EFNA1) is also known as EPLG1, LERK1, TNFAIP4, Immediate early response protein B61, which belongs to the ephrin family. EFNA1 contains one ephrin RBD (ephrin receptor-binding) domain. EFNA1 is cell surface GPI-bound ligand for Eph receptors, and is a family of receptor tyrosine kinases which are crucial for migration, repulsion and adhesion during neuronal, vascular and epithelial development.