In order to assess the importance of Tregs in regulating DTHA severity, we selectively depleted Tregs by administration of DT at 24 and 48 h after arthritis induction to Foxp3-DTR-eGFP mice (FoxP3-DTR+) and littermate controls (FoxP3-DTR−). The gene discussed is FOXP3; the disease is arthritic joint disease.