We are investigating basic and applied immunological studies of human histocompatibility leukocyte antigen (HLA). HLA molecules are expressed on the cell surface, and T lymphocytes recognize antigenic peptides in the context of HLA molecules through recognition by T cell receptor. Subsequently Tlymphocytes are activated to kill infected or tumor cells, or produce cytokines to activate other cells to remove antigens.Recent objectives of our researches are as follows. 1)Identification of immunogenic tumor -specific antigens, and basic and applied researches of tumor immunity, 2) Basic and applied immunological researches of dendritic cells differentiated in vitro from mouse, monkey, and human embryonic stem cells, and iPS cells, 3) Analyses of inhibitory mechanism(s) for T cells in tumor-bearing hosts.