Receptor tyrosine kinase which binds promiscuously transmembrane ephrin-B family ligands 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. Generally has an overlapping and redundant function with EPHB2. Like EPHB2, functions in axon guidance during development regulating for instance the neurons forming the corpus callosum and the anterior commissure, 2 major interhemispheric connections between the temporal lobes of the cerebral cortex. In addition to its role in axon guidance also plays an important redundant role with other ephrin-B receptors in development and maturation of dendritic spines and the formation of excitatory synapses. Controls other aspects of development through regulation of cell migration and positioning. This includes angiogenesis, palate development and thymic epithelium development for instance. Forward and reverse signaling through the EFNB2/EPHB3 complex also regulate migration and adhesion of cells that tubularize the urethra and septate the cloaca. Finally, plays an important role in intestinal epithelium differentiation segregating progenitor from differentiated cells in the crypt. ATP + L-tyrosyl-[protein] = ADP + H(+) + O-phospho-L-tyrosyl-[protein] Heterotetramer upon binding of the ligand. The heterotetramer is composed of an ephrin dimer and a receptor dimer. Oligomerization is probably required to induce biological responses (By similarity). Expressed in cells of the retinal ganglion cell layer during retinal axon guidance to the optic disk. Expressed by Paneth and progenitor cells in the crypts of the intestinal epithelium (at protein level). Expressed in myogenic progenitor cells (PubMed:27446912). Expressed during development in yolk sacs and by embryonic endothelial cells. Expressed in the developing intestinal epithelium at the bottom of the intervillus pockets where undifferentiated cells are allocated (at protein level). In myogenic progenitor cells, highly expressed during early development (11.5 dpc) and progressively repressed as developments proceeds (PubMed:27446912). Phosphorylated. Autophosphorylates upon ligand-binding. Autophosphorylation on Tyr-609 is required for interaction with SH2 domain-containing proteins (By similarity). Ubiquitinated by RNF186, mainly through 'Lys-48' and 'Lys-63'-linked polyubiquitin chains. Mice are viable and fertile and show no obvious abnormal behavior. The corpus callosum, the main axon tract connecting the left and right cerebral hemispheres, is not formed in a significant fraction of newborns. This is associated with defects in guidance of callosal axons across the midline. Belongs to the protein kinase superfamily. Tyr protein kinase family. Ephrin receptor subfamily.