MRC1 and rheumatoid arthritis: We compared the expression of surface markers that have previously been identified on RA CD1c+ DCs.21, 29 We found that the expression of CD14, CD11b, CD206 and Signal-regulatory protein alpha (SIRPα) was concordant between RA-SF and synovial tissue CD1c+ DCs and our induced CD1c+ population (see online supplementary figure S1) but expression of both FcεRI and Dendritic Cell-Specific Intercellular adhesion molecule-3-Grabbing Non-integrin (DC-SIGN) was lower.