[1] FREE UNIV AMSTERDAM HOSP,DEPT PEDIAT,AMSTERDAM,NETHERLANDS
[2] UNIV HAMBURG,KRANKENHAUS EPPENDORF,W-2000 HAMBURG 20,GERMANY
[3] FREE UNIV HOSP BERLIN,BERLIN,GERMANY
[4] DUTCH CHILDHOOD LEUKEMIA STUDY GRP,THE HAGUE,NETHERLANDS
[5] SOPHIA CHILDRENS UNIV HOSP,ROTTERDAM,NETHERLANDS