This Human IL-27 ELISA Ready-SET-Go!® set includes all of the necessary buffers and reagents to perform enzyme-linked immunosorbent assays. This kit allows the specific detection of IL-27 with no detection of IL-35 or free p28 or EBI3. This set has been optimized for the accurate and precise measurement of human IL-27 in serum, plasma, and tissue culture supernatant samples. Serum and plasma samples must be diluted 2-fold in prepared assay diluent prior to evaluation in this ELISA. IL-27 is a member of the IL-12 family, a subgroup of the IL-6 family of cytokines. It is a heterodimer of the subunits EBI3 (Epstein-Barr Virus Induced Gene 3), which is homologous to the p40 subunit shared by IL-12 and IL-23, and p28 (IL-30), which is homologous to p35. IL-27 is produced by activated dendritic cells and macrophages in response to TLR ligands and inflammatory cytokines. The IL-27 receptor shares one subunit, gp130, with other members of the IL-6 family. The subunit WSX-1 (IL-27R alpha, TCCR) is unique to IL-27 and is believed to be the only part of the receptor that interacts with the cytokine. The IL-27R is most abundantly expressed on activated T-cells and NK cells, although expression has also been shown on B-cells and naïve T-cells. IL-27R activation leads to the phosphorylation of Jak/STAT proteins, with STAT1 and STAT3 being critical to the function of IL-27. IL-27 has been shown to have both pro-inflammatory and anti-inflammatory effects. It influences the commitment of CD4+ T-cells toward the Th1 lineage by inducing the expression of the T-bet transcription factor and the upregulation of IL-12R beta2. Its anti-inflammatory functions include the suppression of Th2 and Th17 proliferation and differentiation. Susceptibility to T-cell mediated autoimmunity has been observed in WSX-1 knockout mice.