[1] Univ Bern, Dept Clin Res, Bern, Switzerland
[2] Novartis Inst Funct Genom, Canc Stem Cell Program, San Diego, CA USA
[3] MLL Munich Leukemia Lab, Munich, Germany
[4] Univ Hosp Bern, Inselspital, Dept Hematol, CH-3010 Bern, Switzerland
[5] Univ Hosp Bern, Inselspital, Dept Med Oncol, CH-3010 Bern, Switzerland
[6] Scripps Res Inst, Dept Mol & Expt Med, La Jolla, CA 92037 USA