IL-21 and Related Diseases

IL-21, which is produced by activated NKT cells and CD4+ T cells, exhibits pleiotropic effects not only on a variety of immune cells but also on non-immune cells. It has been demonstrated that IL-21 plays significant roles in the process of autoimmune diseases, inflammatory diseases and cancers. This review intends to give the reader an overview of this cytokine and the relationships between IL-21 and the related diseases of different body systems.