Given that both the Treg/CD4+ ratios (Fig. 2, A and B) and absolute numbers of Treg cells (Fig. 2C) are largely similar in peripheral lymph nodes derived from either Foxp3Cre;Ube2mfl/fl;Ube2ffl/fl or Foxp3Cre control mice around p20, we hypothesized that the severe inflammation disorders observed in Foxp3Cre;Ube2mfl/fl;Ube2ffl/fl mice at the same age is most likely attributable to the loss of the suppressive function of Treg cells. Here, CD4 is linked to inflammation.