IL4R and allergic asthma: Eosinophils, which are central to the pathogenesis of allergic and non-allergic asthma [54,55], express high levels of surface IL-5Rα chain [56], as well as TSLPR [57], the IL-4Rα chain common to IL-4R and IL-13R [58,59], and the high-affinity receptor FcεRI [60].