IL4 and allergic disease: In allergic diseases, histamine, TNF-α, and IL-1 released from mast cells by IgE-mediated inflammatory reactions and activation of Th2 cells, a type 2 helper T cell, which secrete a variety of proinflammatory cytokines such as IL-4, IL-5, and IL-13 play an important role and besides the roles of regulatory T cells and helper T cells such as Th1 and Th17 are involved in the regulation of allergic inflammatory reactions [4, 5].