Interleukin 26
Interleukin-26 (IL-26) is a protein that in humans is encoded by the IL26 gene.
IL-26 is the most recently identified member of the IL-20 cytokine subfamily, which was formed according to the usage of common receptor subunits and similarities in target-cell profiles and functions. All cytokines belonging to this subfamily are members of the larger IL-10 family. IL-26 is expressed in certain herpesvirus-transformed T cells but not in primary stimulated T cells. IL-26 signals through a receptor complex comprising two distinct proteins called IL-20 receptor 1 and IL-10 receptor 2. By signaling through this receptor complex, IL-26 induces rapid phosphorylation of the transcription factors STAT1 and STAT3, which enhance IL-10 and IL-8 secretion and as expression of the CD54 molecule on the surface of epithelial cells.