TNFSF14, also known as tumor necrosis factor ligand superfamily member 14 or LIGHT (homologous to lymphotoxins, exhibits inducible expression, and competes with HSV glycoprotein D for HVEM, a receptor expressed by T lymphocytes), is a cytokine belonging to the tumor necrosis factor (TNF) superfamily. It is expressed on the surface of activated T cells, natural killer cells, and immature dendritic cells. TNFSF14 plays a crucial role in regulating immune responses, inflammation, and lymphoid organ development. It can bind to two receptors, herpes virus entry mediator (HVEM) and lymphotoxin beta receptor (LTβR), and modulate various immune functions, including T cell activation, cytokine production, and lymphoid tissue organization.