Recombinant human IL-32, also known as natural killer cell transcript 4 (NK4) and TNFa-inducing factor., is a 27 kDa secreted glycoprotein that belongs to no known cytokine family. It induces pro-inflammatory cytokines such as TNFa and IL-8, and activates typical cytokine signaling pathways involving NF-?B and p38. Human IL-32 is active in mouse cells, although no rodent orthologs have been reported. It represents the standard protein, one isoform of five potential alternate splice variants, and is involved in activation-induced T cell death and highly expressed in disease states such as the synovial tissue of rheumatoid arthritis and colon epithelial tissue in Crohn’s disease. Increased levels of IL-32 during immunodeficiency virus infection may play a protective role by ? suppressing HIV replication. R&D Systems, 800-343-7475, www.RnDSystems.com