4-1BBL, a member of the TNF superfamily, is expressed in B cells, dendritic cells, activated T cells and macrophages. The soluble form of 4-1BBL contains the TNF-like portion of the extracellular domain of 4-1BBL. Recombinant human 4-1BBL is a soluble 19.5 kDa protein consisting of 185 amino acid residues.
