[1] German Canc Res Ctr, Div Mol Genet, D-6900 Heidelberg, Germany
[2] Univ Heidelberg Hosp, Dept Pediat Oncol Hematol & Immunol, Heidelberg, Germany
[3] Heinrich Heine Univ Duesseldorf, Dept Neuropathol, Dusseldorf, Germany
[4] German Canc Res Ctr, Clin Cooperat Unit Pediat Oncol, Heidelberg, Germany
[5] German Canc Res Ctr, Clin Cooperat Unit, Heidelberg, Germany