S. Baskar a.o.: Constitutive expression of B7 restores immunogenicity of tumor cells expressing truncated major histocompatibility complex class II molecules. Proc. Nat. Ac. Sci. USA 90 (1993), 5687-... L. Chen a.o.: Tumor immunogenicity determines the effect of B7 costimulation on T cell-mediated tumor immunity. J. Exp. Med. 179 (1994), 523-... F. Harding/J. Allison: CD28-B7 interactions allow the induction of CD8+ cytotoxic T lymphocytes in the absence of exogenous help. J. Exp. Med. 177 (1993), 1791-... K. Hathcock a.o.: Comparative analysis of B7-1 and B7-2 costimulatory ligands - expression and functions. J. Exp. Med. 180 (1994), 631-... C. June/J. Bluestone/L. Nadler/C. Thompson: The B7 and CD28 receptor families. Imm. Today 15 (1994), 321-... Ronald Schwartz: Costimulation of T lymphocytes - the role of CD28, CTLA-4, and B7/BB1 in interleukin-2 production and immunotherapy. Cell 71 (1992), 1065-... S. Townsend/J. Allison: Tumor rejection after direct costimulation of CD8+ T cells by B7-transfected melanoma cells. Science 259 (1993), 368-...