1. CD28–B7 interactions in T-cell activation;Allison;Curr. Opin. Immunol,1994
2. Involvement of CD28 in MHC-unrestricted cytotoxicity mediated by a human natural killer leukemia cell line;Azuma;J. Immunol,1992
3. The binding and lysis of target cells by cytotoxic lymphocytes;Berke;Annu. Rev. Immunol,1994
4. A new member of the immunoglobulin superfamily;Brunet;Nature,1987
5. Costimulation of T lymphocytes with integrin ligands intercellular adhesion molecule-1 or vascular cell adhesion molecule-1 induces functional expression of CTLA-4, a second receptor for B7;Damle;J. Immunol,1994