Frozen human synovial tissue section from patient with osteoarthritis was stained with hematoxylin and eosin and Mouse Anti-Human CD55-UNLB (SB Cat. No. 9661-01) followed by a secondary antibody and colorimetric substrate. Image from Mucke J, Hoyer A, Brinks R, Bleck E, Pauly T, Schneider M, et al. Inhomogeneity of immune cell composition in the synovial sublining: linear mixed modelling indicates differences in distribution and spatial decline of CD68+ macrophages in osteoarthritis and rheumatoid arthritis. Arthritis Res Ther. 2016;18:170. Figure 1