Overactivation of BTK is also of great importance in other autoimmune diseases, including Sjögren’s syndrome [313], neuromyelitis optica spectrum disorders (NMOSD) [314], ITP [315], etc. For instance, in ITP, BTKi enhanced platelet numbers by ameliorating Fcγ receptor-mediated platelet destruction by macrophages and decreasing autoantibody generation [91]. The gene discussed is BTK; the disease is autoimmune thrombocytopenic purpura.