Asthma is a T helper 2 (Th2) disease characterised by eosinophilic lung inflammation, mucus production, AHR, Th2 cytokines (interleukin-4 (IL-4), IL-5, and IL-13), and B cells producing IgE (Lambrecht and Hammad, 2015). This evidence concerns the gene IL4 and asthma.