Human TRAIL R2, also known as DR5 and TRICK 2, is a type 1, TNF R family, membrane protein which is a receptor for TRAIL (APO2 ligand). In the new TNF superfamily nomenclature, TRAIL R2 is referred to as TNFRSF10B. TRAIL R2 cDNA encodes a 440 amino acid residue precursor protein containing extracellular cysteine-rich domains, a transmembrane domain and a cytoplasmic death domain. Among TNF receptor family proteins, TRAIL R2 is most closely related to TRAIL R1/DR4, sharing 55% amino acid sequence identity. Binding of trimeric TRAIL to TRAIL R2 induces apoptosis. The induction of apoptosis likely requires oligomerization of the receptor. The human TRAIL R2/Fc chimera neutralizes the ability of TRAIL to induce apoptosis. Besides TRAIL R2, an additional TRAIL R1/DR4, which tranduces apoptosis signaling, and two TRAIL decoy receptors, which antagonize TRAIL-induced apoptosis, have been reported.