Death Domain (DD) found in Uncoordinated-5D (UNC5D). UNC5D is part of the UNC-5 homolog family. It is a receptor for the secreted netrin-1 and plays a role in axonal guidance, angiogenesis, and apoptosis. UNC5 proteins are transmembrane proteins with an extracellular domain consisting of two immunoglobulin repeats, two thrombospondin type-I modules and an intracellular region containing a ZU-5 domain, UPA domain and a DD. In general, DDs are protein-protein interaction domains found in a variety of domain architectures. Their common feature is that they form homodimers by self-association or heterodimers by associating with other members of the DD superfamily including CARD (Caspase activation and recruitment domain), DED (Death Effector Domain), and PYRIN. They serve as adaptors in signaling pathways and can recruit other proteins into signaling complexes.