CTLA4 and rheumatoid arthritis: The U.S. Food and Drug Administration approved the first tumour necrosis factor inhibitor (TNFi) to treat RA in 1999, the first cytotoxic T-lymphocyte-associated protein 4 immunoglobulin (CTLA-4-Ig) in 2005, and the first interleukin-6 receptor inhibitor (IL-6Ris) in 2010.