The research of the Institute for Asthma and Allergy Prevention (IAP) at Helmholtz Zentrum München is focusing on the underlying mechanisms of asthma and allergies in childhood. The aim is to prevent the development and the manifestation of the disease. To this end, the scientists employ extensive international field and population studies as well as clinical studies and laboratory experiments. One prominent example is the so-called hygiene hypothesis, to which Erika von Mutius, director of IAP, and her team contributed robust evidence.