Along the same lines, a protective, anti-inflammatory function of the IL-33/ST2/MC axis has been described by different studies, including limitation of inflammatory monocyte responses [61], enhancement of regulatory T cells through enhanced IL-2 production [75,76], protection against airway hyperresponsiveness owing to PGE2 generation [77], and MC-dependent restoration of mucosal healing [78]. This evidence concerns the gene IL33 and airway hyperresponsiveness.