title: Living with the ups and downs of the two signal model.
authors.affiliation: Department of Microbiology and Immunology, The University of Saskatchewan, Saskatoon, Saskatchewan, Canada. bretsch@duke.usask.ca
authors.forename: Peter
authors.initials: P
authors.lastname: Bretscher
mesh_terms: D000818:Animals; D006801:Humans; D008213:Lymphocyte Activation / Q000276:immunology*; D008214:Lymphocytes / Q000276:immunology*; D017634:Self Tolerance / Q000276:immunology*; D013950:Thymus Gland / Q000276:immunology