FOXP3 and autoimmune disease: In the DEREG (‘depletion of regulatory T cell’) model, in which DTR/GFP is expressed from a transgenic Foxp3 bacterial artificial chromosome (Foxp3BAC-DTR/GFP), administration of DT into newborns resulted in scurfy-like symptoms, while adults were found to be protected from autoimmune diseases, despite efficient GFP+ Treg cell depletion (9).