To directly explore whether Mbd2 deficiency in CD4 T cells was responsible for the observed phenotype, we adoptively transferred CD4 T cells isolated from new-onset diabetic Mbd2−/− NOD mice and control littermates into 5-week-old NOD.scid (immune-deficient) recipients, followed by monitoring diabetes incidence (Fig. 3A). Here, MBD2 is linked to diabetes mellitus.