IL-17 family: Cytokines, receptors and signaling.

Highlights: [•] IL-17 is essential for host defense against microbial pathogens. [•] IL-17 signaling is tightly controlled at different levels of the signaling cascade. [•] Things can go wrong: pathogenic roles of IL-17 in autoimmunity. [•] IL-17 contributes to intestinal inflammation and tumorigenesis. [•] IL-17E potentiates type 2 allergic responses. [Copyright &y& Elsevier]