RAG1 and diabetes mellitus: Transgenic expression of the BDC2.5 TCR efficiently prevents the development of spontaneous autoimmune diabetes in immunocompetent NOD females [74] but dramatically accelerates diabetes progression in immunodeficient NOD mice, such as NOD.TCR-β−/− or NOD.Rag1−/− mice [74], as well as in NOD.Foxp3−/− mice [54].