Interleukin-32 (IL-32), also designated Natural Killer (NK) cell transcript 4 (nk4), may play a role in inflammatory responses such as lymphocyte activation. IL-32 is secreted following stimulation with inflammatory cytokines such as IL-1(beta) and IFN-(gamma), and by NK cells after exposure to IL-12 and IL-18. It also induces production of IL-1(beta), TNF(alpha), MIP-2 and IL-6. Expression of IL-32 increases after activation of T cells by mitogens or activation of NK cells by IL-2. The IL-32 protein contains three potential N-myristoylation sites, a tyrosine sulfation site, an RGD cellattachment sequence and multiple putative phosphorylation sites. Human IL-32 exists as four isoforms.