The increased CXCL12 endothelial labelling observed in RA tissues by immunohistoshemistry might therefore relate to a higher amount of exogenous CXCL12 docking onto RA vessels, but it might also relate to specific changes in ECs present in the inflammatory environment, as suggested by our observation of stronger CXCL12 display by HEV-type vessels. The gene discussed is CXCL12; the disease is rheumatoid arthritis.