title: Tug of war at the exit door.
abstract: The lipid sphingosine-1-phosphate has been identified as a key exit signal for lymph nodes. In this issue of Immunity, Pham et al. (2008) show that its action can only be understood in the context of retention signals transduced by CCR7.
authors.affiliation: The Helen L. and Martin S. Kimmel Center for Biology and Medicine at the Skirball Institute for Biomolecular Medicine, New York University School of Medicine, 540 First Avenue, New York, NY 10016, USA. dustin@saturn.med.nyu.edu <dustin@saturn.med.nyu.edu>
authors.forename: Michael L
authors.initials: ML
authors.lastname: Dustin
authors.forename: Arup K
authors.initials: AK
authors.lastname: Chakraborty
mesh_terms: D000818:Animals; D002634:Chemotaxis, Leukocyte / Q000276:immunology*; D008198:Lymph Nodes / Q000276:immunology* / Q000378:metabolism; D008246:Lysophospholipids / Q000276:immunology* / Q000378:metabolism; D054400:Receptors, CCR7 / Q000276:immunology* / Q000378:metabolism; D013110:Sphingosine / Q000031:analogs & derivatives* / Q000276:immunology / Q000378:metabolism; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: C515371:Ccr7 protein, mouse; D008246:Lysophospholipids; D054400:Receptors, CCR7; C060506:sphingosine 1-phosphate; D013110:Sphingosine