title: Protection one cell thick.
abstract: Specific immunity is a layer of defense exquisitely broad, terrifyingly thin, and yet remarkably durable on challenge. In this issue of Immunity, Stemberger et al. (2007) now take this concept to its logical extreme by offering evidence that expenditure of a single lymphocyte yields its own replenishment.
authors: Abramson Family Cancer Research Institute and Department of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
authors: John T
authors: JT
authors: Chang
authors: Steven L
authors: SL
authors: Reiner
mesh_terms: D000818:Animals; D018414:CD8-Positive T-Lymphocytes / Q000166:cytology* / Q000276:immunology; D002454:Cell Differentiation; D006412:Hematopoietic Stem Cells / Q000166:cytology*; D007109:Immunity; D007156:Immunologic Memory; D051379:Mice