TNF and rheumatoid arthritis: The TNF-induced gene expression signature in synovial fibroblasts contained more than 50% interferon response genes (53), including many genes with a key role in the pathogenesis of RA [STAT1, CXCL9, CXCL10, B-cell activating factor/tumor necrosis factor superfamily member 13B (BAFF/TNFSF13B)] (Figure 1).