IL13 and cystic fibrosis: In addition to the well-documented IL-13 and eosinophil activity (53, 54), research has also indicated the regulation of thioredoxin, including the reduction of goblet cell proliferation (55), eosinophil infiltration (56), the viscosity of cystic fibrosis sputum (57), and leukocyte infiltration into sites of inflammation (58), which contributes to the allergic symptoms.