Immunolocalization of ADAM15, VEGFR-2, vWF and CD31 in rheumatoid arthritis (RA) synovial tissues. Paraffin sections were stained with (a) hematoxylin and eosin or immunostained with antibodies against (b) ADAM15, (c) VEGFR-2, (d) vWF or (e) CD31, or (f) non-immune mouse IgG as described in Materials and methods. (b) Note that ADAM15 is expressed in synovial lining cells and endothelial cells of blood vessels in the sublining layer. Immunostained sections were counterstained with hematoxylin. Arrows, synovial lining cells; arrowheads, endothelial cells of blood vessel. Scale bar, 100 μm.