IL4 and asthma: A high level of IL-10 was observed in virus-induced asthma; however, IL-10 was reported to inhibit the onset of asthma by inhibiting Th2 cytokine production as well as eosinophil infiltration, and the reduction of IL-10 and the increase of IL-4/IFN-γ (interferon-gamma) lead to the onset of severe asthma [23], [24], [25].