Endothelial orphan receptor that acts as a key regulator of angiogenesis. Heterodimer of 2 chains generated by proteolytic processing; the large extracellular N-terminal fragment and the membrane-bound C-terminal fragment predominantly remain associated and non-covalently linked. Detected in the majority of epithelial cells in tumor and normal tissues. Expressed also in human umbilical vein endothelial cells. Up-regulated in the adult heart. Up-regulated in tumor endothelial cells. Up-regulated by DLL4. The transmembrane domain is not required for cleavage, but it is required for dimer formation. Glycosylated. Proteolytically cleaved into 2 subunits, an extracellular alpha subunit and a seven-transmembrane subunit. Belongs to the G-protein coupled receptor 2 family. Adhesion G-protein coupled receptor (ADGR) subfamily.