IL5RA and asthma: Catalpol, a major component of Rehmanniae Radix, not only reduced transforming growth factor (TGF-β1) and epidermal growth factor (EGF), which are important factors in lung tissue damage and airway remodeling [52], but also lowered IL-4 and IL-5 and inhibited eosinophil infiltration and increase of CCL11, CCR3, and IL-5Rα in the OVA-induced asthma model [53].