TNF and rheumatoid arthritis: The expression of AT2R in cultured FLS from healthy (H-FLS), OA (OA-FLS) and RA (RA-FLS) synovium was investigated by fluorescence immunocytochemistry and Western blotting at baseline and after treatment with the pro-inflammatory cytokines TNF-α and IL-1β, alone or in combination (Fig. 3a,b).