Over the past two decades, attempts have been made to develop immunotherapy for patients with cancer. A significant obstacle to the development of successful adoptive immunotherapy has been the availability of appropriate cytotoxic cells. Immunologic effector cells such as lymphokine-activated killer (LAK) cells, activated T cells such as tumor-infiltrating lymphocytes (TILs), and cytokine-induced killer (CIK) cells may be suitable to remove residual tumor cells.