Mouse Interleukin-23 (IL-23) is a heterodimeric cytokine of approximately 60kDa. It is composed of two subunits, a p19 subunit that is unique to IL-23 (the IL-23 alpha subunit), and a p40 subunit that is shared with IL-12. IL-23 is an important part of the inflammatory response against infection. It promotes up-regulation of the matrix metalloprotease MMP9, increases angiogenesis and reduces CD8+ T cell infiltration. Recently, IL-23 has been implicated in the development of cancerous tumors. In conjunction with IL-6 and TGF-β1, IL-23 stimulates naive CD4+ T cells to differentiate into a novel subset of cells called Th17 cells, which are distinct from the classical Th1 and Th2 cells. Th17 cells produce IL-17, a proinflammatory cytokine that enhances T cell priming and stimulates the production of proinflammatory molecules such as IL-1, IL-6, TNF-α, NOS-2, and chemokines resulting in inflammation. The monoclonal antibody used in this ELISA is allele-specific. It recognizes IL-23 variant with methionine at residue 169. For non-allele-specific, it is available upon request.