CD1D and arthritic joint disease: Oleinka et al. described a role for CD1d+ Transitional 2-Marginal Zone Precursor (T2-MZP) Bregs in the differentiation of suppressive iNKT cells that inhibited pro-inflammatory Th1 and Th17 responses in the context of experimental arthritis, partially via the production of interferon (IFN)-γ.