Regarding allergic diseases, although the onset of acute atopic dermatitis is strongly associated with the production of Th2 cytokines, notably IL-4, IL-5, IL-13 and IL-31, the expression of IFN-γ and IL-17 rather than IL-4 predominates in older lesions, indicating a cytokine switch from Th2 in the acute phase towards Th1 in the chronic phase [94]. Here, IL4 is linked to allergic disease.