Correction to: Mucosal Immunology (2011) e-pub ahead of print 6 April 2011; doi: 10.1038/mi.2011.18

The affiliations listed for Daniele Piomelli were incorrect. They should have been Departments of Pharmacology and Biological Chemistry, University of California, Irvine, Irvine, California and Unit of Drug Discovery and Development, Italian Institute of Technology, Genoa, Italy. The authors regret the error.