IL17A and infection: This was supported by the mechanistic study showing that IL-17 acted as a mediator of IL-1β-induced neutrophilia in influenza-induced COPD exacerbations in mice, and inhibition of IL-17 reduced neutrophil recruitment to the airways both in the initial phase of infection and at the peak of viral replication.57 Therefore, biologic effects of statins in COPD demonstrated in the current study may explain the findings from the observational studies.