Interleukin 25 (IL-25) is also known as IL-17E and belongs to the IL-17 family and is secreted by Tʜ2 cells and mast cells. It induces the production of other cytokines by Tʜ2 cells and ILCs, including IL-4, IL-5, and IL-13 in multiple tissues. IL-25 is an important cytokine controlling the immunity of the gut and can be involved in chronic inflammation associated with the gastrointestinal tract. It is also involved in allergic airway inflammation and airway hyper reactivity. In addition, it shows anti-tumor activity in vivo
in several human cancers including melanoma, breast, and lung.