1 Mucosal Immunology Unit, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA. [email protected]
In this issue of Immunity, Zhang et al. (2009) propose that Treg cells, in order to efficiently control alloimmune response, need to be educated first in the target tissue before entering the draining lymph node.