Description_x000D_ General description_x000D_ By ELISA, the antibody shows approximately 50% cross-reactivity with recombinant human ephrin-A5 and no cross-reactivity with recombinant mouse ephrin-A1, mouse ephrin-A2, human ephrin-A3, mouse ephrin-B1, mouse ephrin-B2, and mouse ephrin B3._x000D_ Immunogen_x000D_ recombinant human ephrin-A4, extracellular domain, expressed in NSO cells._x000D_ Physical form_x000D_ Lyophilized from a 0.2 μm filtered solution in phosphate buffered saline._x000D_ Biochem/physiol Actions_x000D_ Ephrin A4 binds to EPH receptor A4, a protein-tyrosine kinase family that belongs to the ephrin receptor subfamily. The ephrin-A and ephrin-B ligands and regulate developmental events, particularly those of the nervous system. EphrinA4 regulates the axonal growth, astrocyte reactivity and neuroinflammation in experimental autoimmune encephalomyelitis. High expression of EphA4 receptor correlates with tumor progression, invasion and metastasis of gastric cancer and is a suitable prognostic marker.