IL17A and fungal infectious disease: Aside from the previously discussed role of IL-17 in the defense against fungal infections, this might be explained by the importance of IL-17 for the maintenance of gastrointestinal barrier integrity: IL-17A-dependent signaling regulates the tight junction protein occludin, and subsequently, IL-17 neutralization increases gut permeability in a DSS (Dextran sulfate sodium)-induced colitis mouse model [257, 258].