IL4 and asthma: The best known phenotype of asthma is allergic asthma, in which these symptoms are caused by inhaled allergens such as house dust mites, animal dander, fungi, and pollens (Kudo et al., 2013), triggering an immunological response driven by T helper type 2 (Th2) cells and their associated cytokines IL-4, IL-5, and IL-13 (Lloyd and Hessel, 2010).