TNFRSF14 is a type I membrane protein belonging to the TNF receptor superfamily. This receptor mediates herpes virus entry into cells during infection. TNFRSF14 is able to inhibit the proliferation, activation, and cytokine production of T cells. It has an extracellular domain containing several cysteine-rich repeats and a short cytoplasmic region containing a TRAF (TNF receptor-associated factor) interaction domain. The extracellular domain of TNFRSF14 interacts with the herpes simplex virus envelope glycoprotein D. TNFRSF14 binds two cellular ligands: lymphotoxin alpha and LIGHT. LIGHT is a transmembrane protein expressed and shed from the surface of activated T cells, exhibits inducible expression, and competes with HSV glycoprotein D for HVEM, a receptor expressed by T lymphocytes. The LIGHT:TNFRSF14 interaction controls immune response functions by cell death induction as well as cell activation. TNFRSF14 is expressed by peripheral blood T cells, B cells, monocytes and in various tissues enriched in lymphoid cells.