Many studies using in vivo animal models and Syk knock-out experiments have demonstrated that Syk is involved in various inflammatory diseases, such as RA, allergic asthma/rhinitis, intestinal ischemia reperfusion injury, SLE, and idiopathic thrombocytopenic purpura (ITP), and that Syk inhibition could be a therapeutic strategy for the treatment of these inflammatory diseases [98–103]. Here, SYK is linked to autoimmune thrombocytopenic purpura.