FUT4 and rheumatoid arthritis: Collectively, this indicates that HLA-DR-positive phenotypes other than B cells, monocytes, and dendritic cells are increased in patients with RA and that these phenotypes share features of granulocytes (CD15 and CD16, high side scatter) while also expressing markers associated with co-stimulation (CD275, ICOS-L) and dendritic-cell-associated molecules CD83 (18) and CD303 (20).