CASP1 and airway hyperresponsiveness: Bauer et al showed that Casp1-/- mice had reduced airway hyperresponsiveness (AHR) to methacholine challenge, but also had increased neutrophilic infiltration and airway inflammation, suggesting that caspase-1 may play opposing roles in allergic airway disease through 1) protection against airway inflammation, and 2) enhancement of allergen-induced AHR [49].