CD30 ligand (CD30L) is a type-II membrane-associated glycoprotein protein belonging to the TNF superfamily and is expressed primarily on certain B cells, T cells, and monocytes. CD30L binds specifically to CD30 (receptor), which is expressed on activated, but not resting, B and T cells, in lymphomas and various chronically inflamed tissues. CD30L/CD30 interactions initiate a signaling cascade that can ultimately lead to the activation of NF-KappaB. CD30L/CD30 signaling exerts pleiotropic effects on normal cells, including cell death, differentiation, or cell division. Certain diseases, including Hodgkins’s lymphoma, allergic inflammation, diabetes (in NOD mice), and mycobacterial infection can also be affected by CD30L/CD30 signaling. The CD30L gene encodes for a 234 amino acid type II transmembrane protein, which contains a 37 amino acid cytoplasmic sequence, a 25 amino acid transmembrane domain and a 172 amino acid extracellular domain. Recombinant human soluble CD30L (sCD30L) is a 188 amino acid polypeptide corresponding to the extracellular domain, and contains an 8 residue N-terminal His -Tag.