Tumor necrosis factor receptor superfamily member 25 (TNFRSF25) contains 1 death domain and 4 TNFR-Cys repeats. TNFRSF25 is a cell surface receptor of the tumor necrosis factor receptor superfamily which mediates apoptotic signalling and differentiation, activated by a monogamous ligand, known as TL1A (TNFSF15), which is rapidly upregulated in antigen presenting cells and some endothelial cells following Toll-Like Receptor or Fc receptor activation. This receptor has been shown to signal both through the TRADD adaptor molecule to stimulate NF-kappa B activity or through the FADD adaptor molecule to stimulate caspase activation and regulate cell apoptosis. It may play a role in regulating lymphocyte homeostasis.