Receptor for members of the ephrin-B family. ATP + L-tyrosyl-[protein] = ADP + H(+) + O-phospho-L-tyrosyl-[protein] Most abundant in thymus and detectable in brain, retina, kidney, lung and heart. Not detected in skeletal muscle and liver. Belongs to the protein kinase superfamily. Tyr protein kinase family. Ephrin receptor subfamily.