[1] Univ Munster, Dept Pediat Hematol Oncol, D-4400 Munster, Germany
[2] MC Sophia Childrens Hosp, Dept Pediat Hematol Oncol, Rotterdam, Netherlands
[3] Univ Schleswig Holstein, Dept Pediat, Kiel, Germany
[4] Jackson Lab, Bar Harbor, ME 04609 USA
[5] Univ Newcastle Upon Tyne, No Inst Canc Res, Newcastle Upon Tyne NE1 7RU, Tyne & Wear, England