However, non-T2 cytokines have also been implicated in asthma pathogenesis, including IL-17A,4, 5 IL-6,6 and IFN-γ.7, 8, 9 IFN-γ and IFN-γ–inducible type 1 (T1) immune gene expression is increased in the airways of a proportion of patients with severe asthma,7, 8, 9, 10 and IFN-γ drives corticosteroid-refractory airway hyperresponsiveness (AHR) in a murine severe asthma model.9 This evidence concerns the gene IL17A and airway hyperresponsiveness.