CD55 and rheumatoid arthritis: The co-localisation of 1325:01B09 binding sites with CD55-positive (figure 6C) and PDPN-positive FLS (figure 6D), as well as co-localisation of the F(ab’)2 1325:01B09 fragments with PDPN-positive FLS (figure 6E) was further confirmed in two additional inflamed RA synovial tissue using confocal microscopy.