title: New battlefields for costimulation.
abstract: Costimulation regulates the activation of naive T cells as they first encounter antigens in the secondary lymphoid organs. But recently characterized costimulatory molecules of the B7 family appear to have roles beyond initial T cell activation. New evidence shows that negative costimulators expressed by tumors and normal tissues afford local protection from T cell-mediated attack.
authors.affiliation: Department of Immunology, MD Anderson Cancer Center, Houston, TX 77030, USA. nmorozco@mdanderson.org
authors.forename: Natalia
authors.initials: N
authors.lastname: Martin-Orozco
authors.forename: Chen
authors.initials: C
authors.lastname: Dong
mesh_terms: D000818:Animals; D006801:Humans; D008213:Lymphocyte Activation / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology*