title: Regulatory T cell differentiation: turning harmful into useful.
abstract: In this issue of Immunity, Lee et al. (2012) demonstrate a surprisingly broad "window of opportunity" for regulatory T (Treg) cell induction and provide evidence for an avidity model of Treg cell differentiation versus deletion.
authors.affiliation: Institute for Immunology, University of Munich, Goethestrasse 31, 80336 Munich, Germany. ludger.klein@med.lmu.de
authors.forename: Ludger
authors.initials: L
authors.lastname: Klein
authors.forename: Ksenija
authors.initials: K
authors.lastname: Jovanovic