title: Polarized radicals.
abstract: Establishing polarized surfaces enables cells to carry out specialized tasks. In this issue, Lee et al. present a mechanism for cell polarization in which localized peroxidases are used to position the Casparian strip, a diffusion barrier deposited between endodermal cells in plant roots.
authors.affiliation: Department of Biology, Duke Center for Systems Biology, Duke University, Durham, NC 27708, USA.
authors.forename: Louisa M
authors.initials: LM
authors.lastname: Liberman
authors.forename: Philip N
authors.initials: PN
authors.lastname: Benfey