In the present study, we found that PGC-1β was expressed in lining cells (both macrophage-like synoviocytes and fibroblast-like synoviocytes) and sublining inflammatory cells (mostly in lymphocytes and plasma cells), and PGC-1β expression in RA synovium was significantly higher than that in OA or Orth.A synovium. The gene discussed is PPARGC1B; the disease is rheumatoid arthritis.