TNFSF13B and rheumatoid arthritis: In addition to rituximab, anti-BAFF (B cell activating factor), which is a member of the tumor necrosis factor (TNF) family of BAFF/B lymphocyte stimulator (BLyS) agents, is effective for the treatment of systemic lupus erythematosus (SLE) [34], and TNF-alpha inhibitors were useful as the first immunobiological agent used to treat rheumatoid arthritis [35].