 Nasal mucus and nasal epithelium are the first defense barriers against allergens. Various proteins are found in nasal mucus that play a role in allergic rhinitis and reflect immune response to allergen exposure. The difference in the proteomic profile of allergic rhinitis patients and healthy controls can give insight about how the response works and which proteins could lead to either enhanced immune reaction or to defense response like augmentation of epithelial integrity. It is also known that the airway epithelium plays a crucial role in the regulation of airway immune responses and inflammation. Gene expression profiling is widely used to analyses complex disease. For the airway epithelium gene expression profile in diseased and healthy state as well as in baseline and provoked state can clarify the mechanism of defense reactions and the course of inflammatory processes. Nasal mucus proteins as consequence of different gene expression can be seen as part of the end products of this complex mechanisms and interactions between allergens and the epithelium. 