PRDM1 and diabetes mellitus: Immune tolerance regulation involves critical factors like B-lymphocyte-induced maturation protein 1 (Blimp-1), encoded by Prdm1, a master regulator of B- and T-cell differentiation and activation.12, 13, 14 We previously demonstrated that Blimp-1 overexpression in T cells protects against diabetes and MOG35–55-induced encephalomyelitis in non-obese diabetic (NOD) mice, whereas its deletion increases Th1/Th17 responses and exacerbates encephalomyelitis.15