Animal models are useful and can closely mimic clinical features of asthma, mainly airway hyperreactivity (AHR), which relies on T-helper 2 (Th2) cytokine secretion; interleukin (IL)-5 promotes eosinophil recruitment to the lungs, while IL-13 induces goblet cell hyperplasia and mucus production3. Here, IL13 is linked to asthma.