Serum levels of hepatocyte growth factor (HGF) and HGF and c-Met expression in the synovium. (A) The histologic feature of swollen joints 60 days after induction of arthritis in SKG mice expressed HGF and c-Met in the synovium. Original magnification, ×200; inset, ×400. (B) The serum levels of HGF in β-glucan-injected SKG mice (60 days after induction) were higher than in untreated SKG mice. Data are represented as the means ± SD (n = 4). *P = 0.06. (C) The histologic feature of joints in RA patients expressed HGF and c-Met in the synovium (BV, blood vessel; F, fibroblastic cell; M, mononuclear cell; OA, osteoarthritis; RA, rheumatoid arthritis; SL, synovial lining cell layer). Original magnification, ×100; inset, ×400. We examined the histologic features of joints in osteoarthritis patients as a control.