Interleukin 32 (IL-32),previously known as a transcript (NK4), is produced by mitogen-activated lymphocytes, by IFNgamma-activated epithelial cells or by IL-12 and IL-18-activated NK cells.Its expression is increased following activation of T-cells by mitogens or the activation of NK cells by IL-2.IL-32 activates NF-κ-B and p38 MAPK cytokine signal pathways. It has been suggested that IL-32 may play a role in autoimmune and inflammatory diseases such as rheumatoid arthritis.IL-32 is unusual in that it does not share sequence homology with known cytokine families and is highly expressed in immune tissues. IL-32 exists in at least four differentially spliced isoforms (alpha, beta, gamma and delta)with predicted molecular weight: ~26 kD.IL-32alpha is the shortest and most abundant of four potential splice variants of the pro-inflammatory cytokine IL-32.Potential modifications include myristoylation and N-glycosylation. Transfected IL-32 alpha was more likely to be cell-associated as compared to IL-32beta, suggesting an intracellular function.