IL4 and allergic asthma: T helper 2 (TH2) cells have a central role in the inflammatory response in allergic asthma, by releasing interleukin-4 (IL-4) and IL-13, both of which stimulate B cells to synthesize IgE, and IL-5 which are necessary for eosinophilic inflammation [16], while suppressing the production of TH1 cell cytokines, e.g.: IFN-γ and IL-2 [17], [18].