The prevalence of allergic diseases and asthma has increased in recent years. This has stimulated intensive research to understand the pathogenesis of these diseases. Indeed, researchers have provided key insights and new concepts that have also changed therapeutic strategies. Moreover, allergic inflammation has been something of a model that helps to further the understanding of regulatory mechanisms of inflammation in general. Here, I would like to mention just a few examples. Allergy research has contributed significantly to our current knowledge in intracellular and extracellular mechanisms of anergy, immunoglobulin class switching, and maturation of antigen-presenting cells. Moreover, the general role of delayed apoptosis to accumulate inflammatory cells as well as the biological functions of at least some cytokines (e.g., IL-4, IL-5, IL-10, IL-13) would not have been fully elucidated without studying allergic inflammation. Finally, immunotherapy represents the only utilized antigen-specific treatment in humans at the moment and, therefore, the insights obtained here are applicable to other forms of vaccination.