Interleukin-13 (IL-13), also known as T-cell activation protein P600, is an immunoregulatory cytokine belonging to the IL-4/IL-13 family. It is produced by activated Th2 cells, mast cells and NK cells. IL-13 signals through a receptor complex composed of IL-4Rα and IL13Rα1 (or IL13Rα2). IL-13 inhibits the expression of inflammatory cytokines such as IL-1β, TNF-α and IL-6 by monocytes and macrophages. It also induces B cell activation and IgE secretion.
