Mucosal tissues including the intestine, lung, reproductive tract, and skin form the major interfaces between the outside and internal milieus. Facing the outside is an epithelial cell layer, the epithelium, built on a vascular connective surface. In addition to performing specialized functions, mucosal tissues are sites where immune, epithelial, and neuronal cell types act in concert to maintain tissue integrity and fight invading pathogens. This article presents the latest findings from my laboratory describing a novel protective function for the intestinal intraepithelial gammadelta T cells (gammadelta intraepithelial lymphocytes).