Purity >90 as determined by SDS-PAGE. Interleukin 17E (IL-17E), also known as IL-25, is a member of the IL-17 family of cytokines. IL-17E binds to the IL-17BR receptor to stimulate the secretion of the proinflammatory interleukin 8 (IL-8) chemokine and to induce the activation of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-?B).