This volume examines all facets of the complex biology of Immunoglobulin E (IgE) antibodies, which play an essential role in the pathophysiology of allergic diseases and immunity to parasites. It highlights the unique mechanisms involved in the regulation of IgE production at both the molecular and cellular level. Furthermore, it discusses in detail novel findings on how the affinity, specificity and cross-reactivity of IgE can fine-tune mast cell responses to allergens. The book also explores the beneficial roles of IgE antibodies in immunity to helminthes and protection against tumors, and how the properties of IgE-mediated immunity are employed in the development of IgE therapeutic antibodies. All chapters were written by respected experts in their fields and will appeal to scientists and clinicians alike.