SLAMF7 and rheumatoid arthritis: Given the strong expression of CD319 in leukocyte infiltrates in RA synovial tissue and the inhibitory activity of PDL241 on Ig production, the ability of PDL241 in modulating inflammatory cellular reactions within an RA lesion was modeled using a PBMC-RA synovial fibroblast (RASF) co-culture [34].