IL17A and autoimmune pancreatitis: In a comparison of the type 1 and the type 2 AIP, Th17-cell infiltrates were significantly more pronounced in the periductal compartment of the type 2 AIP, which was induced via neutrophil recruitment by both IL-17A and the induction of the granulocyte-macrophage colony-stimulating factor secretion, resulting in partial ductal destruction (63).