– Ephrins-A3 belongs the Ephrins ligand family which involved in a variety of biological processes, especially in the nervous system and in erythropoiesis. It is shown that Ephrin-A3 is expressed in brain, skeletal muscle, spleen, thymus, prostate, testis, ovary, small intestine, and peripheral blood leukocytes. Ephrin-A3 has a GPI anchor following the extracellular sequence and a signal sequence of 22 amino acids. Ephrin-A3 can bind EphA2, EphA3, EphA4, EphA5, EphA6, EphA7, EphA8 and EphB1. Futhermore, it is associated with tumor growth and metastasis.