CASP4 and asthma: Activated caspase-11 induces pyroptosis, alveolar macrophages from patients with asthma exhibit increased expression of caspase-4 (human homologue of caspase-11), and prostaglandin E2 can exert protective effects against allergic airway inflammation by inhibiting caspase-11-/caspase-4-dependent pyroptosis in mouse and human macrophages (9).