expression in the RA synovial tissues. Synovial tissue samples from patients with RA (A, B, D) or with OA (C) were stained with anti-CB2 pAb (A B, and C), or normal rabbit IgG (D). All sections were counterstained with hematoxylin. Bar, 400 μm. The representative figures of three RA and three OA synovial tissues are depicted. The severity of the CB2 staining of samples was shown (E). Double immunofluorescence staining of the RA synovial tissues with CB2 and CD68, CD4, CD8, CD21 or vimentin, and DAPI are shown (F). Arrows indicate double-positive cells in the merged image. Bar, 40 μm. *p < 0.05.