| Modification Notes |
Tumor necrosis factor (TNF) and lymphotoxin-a (LT-a, also known as TNFa) are members of a family of secreted and cell surface cytokines that participate in the regulation of immune and inflammatory responses. LT-b (lymphotaxin-b or TNFC) is a type II membrane protein with significant homology to TNF, LT-a and the ligand for the CD40 receptor. LT-a is present on the surface of activated T, B and LAK cells as a complex with LT-b. LT-b, also expressed by active lymphocytes, forms a heterotrimer with LT-a on the cell surface and anchors LT-a to the cell surface. A TNF receptor-related protein, the LT-b receptor (also known as TNFC receptor), is the human receptor for the LT-a/LT-b heterotri-mer. There are two LT-b isoforms expressed in human lymphoid cell lines and non-Hodgkin’s lymphomas. The gene which encodes LT-b maps to the major histocompatibility complex region on human chromosome 6p21.33. |