Fig. 2

Fibroblast-like synoviocytes were observed by scanning electron microscopy. A–C Fibroblast-like synoviocytes from patients with rheumatoid arthritis showing cytoplasmic extensions and the presence of filopodia (white arrow). D–F Fibroblast-like synoviocytes from mice with collagen-induced arthritis showing the presence of filopodia (white arrow)