Although the development of allergic reactions is characterised by a wide heterogeneity, IgE plays a crucial role in bridging innate and adaptive immunopathological events in the continuum of allergic asthma, from allergic sensitization to clinical early and late phases, and its evolution into a chronic condition, by acting on different immune cells and modifying their functions (Figure 2). The gene discussed is IGHE; the disease is allergic disease.