Both CD4+CD25-T cells and CD4+CD25+T cells in indirubin-treated ITP mice showed similar expressions of CD44, CD45, GITR and CD152 as those in ITP mice (data not shown), indicating the surface phenotypes were unaltered after indirubin treatment. The gene discussed is TNFRSF18; the disease is autoimmune thrombocytopenic purpura.