Importantly, they are also prone to asthma exacerbations, which can be partially alleviated by therapeutics that block IL-4, IL-5 or IL-13 and reduce eosinophilic inflammation in the lungs.5 However, the molecular mechanisms that link TH2-induced eosinophilia with susceptibility to exacerbation are yet to be defined. Here, IL13 is linked to asthma.