IGHE and inflammation: In this study, by using SHP-1 deficient and mast cell deficient mice in models of LPS induced airway inflammation, IgE-FcεRI mediated passive systemic anaphylaxis (PSA) and OVA allergen induced active systemic anaphylaxis (ASA), we tested the hypothesis that SHP-1 through regulation of mast cell functions plays a critical role in controlling airway inflammation and anaphylaxis.