PRDM1 and diabetes mellitus: Even though IL-4+CD4+ cells were decreased in spleens of BKTg mice compared with KRc mice, the incidence of autoimmune diabetes in BKTg mice was still reduced in comparison with control and KRc mice (Figure 5A), suggesting that Blimp-1 overexpression mediated a strong protection in BKTg mice and that the decrease of diabetes incidence is not directly influenced by the reduction of IL-4–producing CD4+ T cells.