IL1A and airway hyperresponsiveness: In both humans and mice, O3 causes damage to the airway epithelium, release of acute phase cytokines such as IL‐1α, recruitment of neutrophils and macrophages into the lungs, and airway hyperresponsiveness (AHR), a cardinal feature of asthma (Holtzman et al., 1979; Devlin et al., 1991; Kasahara et al., 2015a; Michaudel et al., 2018).