A Subpopulation of Synovial Fibroblasts Leads to Osteochondrogenesis in a Mouse Model of Chronic Inflammatory Rheumatoid Arthritis.

Specific major histocompatibility complex (MHC) class II genes result in a high susceptibility to rheumatoid arthritis (RA), with co-stimulatory molecules working together with MHC class II during the progression of the disease. To elucidate the involvement of the B7.1 co-stimulatory molecule in RA, we analyzed the phenotype of B7.