To confirm the involvement of CD1d in T2-MZP Breg-suppressive function and in the differentiation of disease-ameliorating iNKT cells, we isolated T2-MZP Bregs from the spleens of WT, Jα18−/−, and Cd1d−/− mice in remission from arthritis and transferred them into WT mice. The gene discussed is CD1D; the disease is arthritic joint disease.