© Springer Science+Business Media, LLC 2012. All rights reserved. The field of cancer immunology and immune therapy has been an important focus of basic and clinical research since early discoveries of tumor antigens and adoptive immunity (Disis et al. 2009; Dougan and Dranoff 2009a, b). As techniques developed that allowed researchers to distinguish various lymphocyte subsets, more-specific strategies began to develop, and included such therapies as IL-2 stimulation of autologous lymphokine activated killer (LAK) cells from peripheral blood and ex vivo culture and activation of tumor-infiltrating lymphocytes (TIL). Most of these studies focused on natural killer (NK) cells or cytotoxic T lymphocytes (CTL) as the primary mediators of antitumor immunity (Yannelli et al. 1996; Bloom et al. 1997; Fleischhauer et al. 1997; Kawakami et al. 1998; Kim et al. 1998; Dudley et al. 1999; Mateo et al. 1999; Colella et al. 2000) and although notable successes have been achieved, most CTL- or NK-based immunotherapeutic strategies have-delivered mixed results. The contribution of γδ T cells, a minor T cell subset with distinct innate immune recognition properties, has not been explored until recently.