IL6 and asthma: However, while high serum IL‐6 is associated with severe asthma in humans (Peters et al., 2016) and while IL‐6 contributes to allergen‐induced AHR in mice (Lin et al., 2016), IL‐6 does not appear to play a role in O3‐induced AHR even though it does contribute to neutrophil recruitment (Johnston et al., 2005b).