Foxp3 and CTLA-4 are selectively expressed by CD45RC^low CD8 T cells. Purified CD4 CD25 T-cell subsets from LEW rats (upper panels) and CD8 CD45RC T-cell subsets (lower panels) were tested for their expression of Foxp3 (A, D), CTLA-4 (B, E), and GITR (C, F) by quantitative RT-PCR as described in “Materials and methods.” The results shown for CD4 T-cell subsets are from 1 representative experiment of 2. The results shown for CD8 T-cell subsets are from 6 to 8 independent experiments. Bars represent the mean values, and filled circles represent the results of each individual experiment. The statistical results of group comparisons (Mann-Whitney U test) are indicated above by horizontal lines.