title: Cell-free factor substitute for "signal 2" in generating cytotoxic reactions.
mesh_terms: D000818:Animals; D003602:Cytotoxicity, Immunologic; D000939:Epitopes; D008211:Lymphocyte Cooperation; D051379:Mice; D013601:T-Lymphocytes / Q000276:immunology*; D014466:Ultraviolet Rays
chemical_list: D000939:Epitopes