1. Department of Medical Oncology, University Hospital Vrije Universiteit, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands, LACDR, Department of Pharmacochemistry, Faculty of Chemistry, Vrije Universiteit, De Boelelaan 1083, 1081 HV Amsterdam, The Netherlands, and Department of Pharmacology and Toxicology, University Maastricht, P.O. Box 616, 6200 MD Maastricht, The Netherlands