Serum thrombopoietin (TPO) levels in patients with amegakaryocytic thrombocytopenia are much higher than those with immune thrombocytopenic purpura. - Mukai, HY; Kojima, H; Todokoro, K; Tahara, T; Kato, T; Hasegawa, Y; Kobayashi, T; Ninomiya, H; Nagasawa, T; Abe, T (Thromb Haemost, 1996)