Fostamatinib (R-406, Table 2) is an oral inhibitor of the spleen tyrosine kinase (Syk) that is converted to the active metabolite, tamatinib, and has been approved for the treatment of chronic immune thrombocytopenic purpura and is being evaluated in other autoimmune disorders, such as rheumatoid arthritis [31]. This evidence concerns the gene SYK and rheumatoid arthritis.