Many intriguing relationships between allergy and cancer continue to pose important unanswered questions. Is there a correlation between IgE and atopy, and cancer? Which are the most important IgE effector cells and do they inhibit or promote tumor growth? Will IgE-mediated antigen uptake and cross-presentation by DCs activate CTLs or Tregs? What animal models are useful in this context and should we design specific anti-tumor immunotherapies, active or passive, based on IgE? Recombinant IgE has already been generated against the tumor-associated antigens folate-binding receptor, HER-2 and EGFR--how to exclude the risk of anaphylaxis in passive immunotherapy with IgE? How can we deal with hypersensitivity to antineoplastic drugs? What is the role of chemotherapeutics and biologicals in the modulation of IgE responses and the impact of the aberrant expression of mutated enzyme AID in cancer tissue? In an effort to survey the state-of-the-art in this area and to answer some of these questions, we invited leaders in the field to participate in a "Symposium-in-Writing". This represents a collection of peer-reviewed papers covering each group's specialist area of expertise. In this way, we aim to target the most important topics in these areas and to provide a comprehensive view of the state-of-the-art in the emerging multi-disciplinary field of "AllergoOncology".