Discription：4-1BBL is a member of the tumor necrosis factor （TNF） receptor family. This receptor contributes to the clonal expansion, survival, and development of T cells. In addition, 4-1BBL expression is found on dendritic cells, follicular dendritic cells, natural killer cells, granulocytes and cells of blood vessel walls at sites of inflammation. The human 4-1BBL gene codes for a 254 amino acid type II transmembrane containing a 28 amino acid cytoplasmic domain, a 21 amino acid transmembrane domain, and a 205 amino acid extracellular domain （ECD） . The human 41BBL ECD shares 32％ and 35％ a.a. identity with murine and rat ECD. Recombinant Human 4-1BB Ligand/TNFSF9 is a 19.4kDa non-glycosylated protein containing 184 amino acid residues.
