Interleukin-23 (IL-23) is a heterodimeric cytokine that belongs to the IL-12 cytokine family. It is composed of two subunits, p19 and p40, with the p40 subunit being shared with IL-12. IL-23 is primarily secreted by activated macrophages and dendritic cells located in peripheral tissues such as skin, intestinal mucosa, and lung. This cytokine plays a crucial role in the development and maintenance of autoimmune inflammation, particularly through its ability to induce IL-17 production, which is a unique role compared to IL-12.
