Tumor Necrosis Factor Receptor Superfamily Member 21 (TNFRSF21) is a type I transmembrane receptor that includes four extracellular cysteine-rich motifs and a cytoplasmic death domain. DR6 is highly expressed in heart, brain, placenta, pancreas, lymph node, thymus and prostate. DR6 may activate NF-kappa-B and JNK to promote apoptosis and T-cell differentiation. In addition, DR6 binds with N-APP, which is released by the deprivation of Trophic-factor. It triggers caspase activation and degeneration of both neuronal cell bodies (via caspase-3) and axons (via caspase-6). DR6 is also expressed on the tumor cell lines and can be induced by TNF-α.