However, in the 1980s, the notion that asthma was nearly always atopic came into prominence [40], which lead to the use of asthma as an exemplar TH2-mediated atopic disease characterized by TH2 cytokines like IL-4, IL-5 and IL-13, eosinophilia and increased IgE production [24–26]. This evidence concerns the gene IL5 and asthma.