CD4 and diabetes mellitus: Although, we have not ruled out the possibility that the CD25+ cells that appear to mediate protection from diabetes in our model could also include other types of regulatory cells, e.g., Th2 cells, the fact that 90% of the CD25+ cells in the pLN of CFA-treated NOD mice expressed Foxp3 tends to favor a traditional CD4+CD25+ regulatory rather than Th2 phenotype.