Figure 1. Tregs in 3- and 10-week-old rats. A: CD4 T cells in spleens of 3- and 10-week-old Lewis rats. Three-week-old rats have significantly fewer CD4 T cells, (n=11, p<0.0001). B: Amount of FoxP3+ CD4 T cells is similar in both age groups (n=11, p=0.85).