Interleukin (IL)‐13 is a pleiotropic cytokine thought to play a key role in T2‐driven inflammation, including eosinophilic inflammation in severe asthma,10 has been implicated in promoting eosinophil survival, activation and recruitment,11, 12, 13 and may also mediate features of airway remodelling relevant to asthma, such as subepithelial fibrosis.14, 15. The gene discussed is IL13; the disease is asthma.