TNF-beta, a member of the tumor necrosis factor family, is a cytokine produced by lymphocytes. It is highly inducible, secreted, and exists as homotrimeric molecule. It forms heterotrimers with lymphotoxin-beta which anchors lymphotoxin-alpha to the cell surface. It mediates a large variety of inflammatory, immunostimulatory, and antiviral responses. It is also involved in the formation of secondary lymphoid organs during development and plays a role in apoptosis.