IL1A and chronic obstructive pulmonary disease: Thus, IL1R–/– mice display reduced capacity to mount Th2 responses to HDM (Willart et al., 2012), while CS-exposed cocultured fibroblasts and bronchial epithelial cells from COPD patients show increased inflammatory response, driven by a stronger IL-1α response than control cocultures (Osei et al., 2016).