ABSTRACTS 5th International Symposium on Leukemia and Lymphoma 12-15 March 2003 Vrije Universiteit, Amsterdam, The Netherlands Organizing committee: G.J.L. Kaspers, VU University Medical Center, Amsterdam, The Netherlands J.J.M. van Dongen, Erasmus MC, Rotterdam, The Netherlands M. Schrappe, Medizinische Hochschule Hannover, Germany A.J.P. Veerman, VU University Medical Center, Amsterdam, The Netherlands Leukemia (2003) 17, 657–674 & 2003 Nature Publishing Group All rights reserved 0887-6924/03 $25.00 www.nature.com/leu