Depletion of Treg cells in TSLPR^−/− mice by injection of anti–IL-7 Ab. Anti–IL-7 (M25) or control antibody (M1) were injected 3 times per week for 4 weeks into either TSLPR^−/− or TSLPR^+/+ littermates. The number of Treg cells in thymus and spleen was determined by staining for intracellular Foxp3. Values shown are for 3 individual mice per group, and the bar indicates the mean in each group.