IL4 and allergic rhinitis: Allergic rhinitis is an IgE-mediated disease that presents with elevated allergen-specific IgE titers, IgE-dependent activations of mast cells, recruitment of activated eosinophils and T cells to mucosal surfaces, inflammation, and disease (Holgate 1999; Kay 2001a,b) T helper (Th) 2 cells contribute to the induction of IgE-mediated disease by overproducing Th2 cytokines (IL-4, IL-5, and IL-13) at the inflammation site (Romagnani et al.