Study the immune response to tumor associated antigens in virus and chemically induced tumors of experimental animals. The following specific areas are being studied: comparison of assays of cellular cytotoxicity, evaluation of normal activity, extraction and isolation of tumor associated antigens, changes in cell surface antigen in tumor lines carried in vivo and in vitro, cryopreservation of cells used in the in vitro assays, inhibition of lymphocyte stimulation and of cell-mediated cytotoxicity and the immunological monitoring of animals undergoing immunological stimulation. Similar studies are in progress in tumor systems of man including the following: evaluation of general immunocompetence of cancer patients, evaluation of responses to tumor associated antigens by leukocyte migration inhibition, lymphocyte stimulation and delayed hypersensitivity utilizing tumor cells and extracts of tumor cells as sources of antigen. Specific protocols using immunotherapy in man are also being studied by clinical trials with immunological monitoring.