[1] Kochi Med Sch, Dept Med, Kochi 783, Japan
[2] Charite, Hosp Benjamin Franklin, Dept Haematol Oncol & Transfus Med, Berlin, Germany
[3] Nagasaki Univ, Sch Med, Dept Haematol, Mol Med Unit,Atom Bomb Dis Inst, Nagasaki 852, Japan
[4] Univ Calif Los Angeles, Sch Med, Div Hematol Oncol, Cedars Sinai Res Inst, Los Angeles, CA USA