Mucosal epithelia line the interior surfaces of the body and account for roughly 75%of the human body’s interface with the environment. The gastrointestinal, respiratory, urinary, and reproductive tracts are all components of the mucosal system. Although each of these tracts serves unique physiological functions, they are also part of a distinct network comprising the common mucosal immune system (Mestecky, 2005a). The combination of physiological functions and external environment drive the immune system at each mucosal surface to make unique and distinct adaptations. For example, the repertoire of commensal organisms typically present on a mucosal surface and pathogenic organisms capable of invading that mucosal barrier are quite