CD28 and sialadenitis: Lastly, unpublished observations from our lab indicate that expression of the P2Y2R is increased in salivary gland-infiltrating B cells in NOD.H-2h4, CD28–/–, IFNγ–/– mice, as compared to B cells isolated from salivary glands of C57BL/6 control mice, and intraperitoneal administration of the selective P2Y2R antagonist AR-C118925 significantly attenuates sialadenitis and restores salivary gland function.