University of Amsterdam - University Medical Center, VU University Amsterdam, Erasmus University Rotterdam (EUR) - Oncode Institute, Maastricht University - Medical Center, Flevoziekenhuis, Dijklanderziekenhuis, Maasstad Hospital, Medical Center Leeuwarden, Meander Medical Center, Erasmus University Rotterdam (EUR) - Department of Hematology, Leuven University Hospital, Jeroen Bosch Hospital, Spaarne Gasthuis, Admiraal De Ruyter Hospital - Department of Internal Medicine, Haga Hospital, Maxima Medical Centre, Radboud University Nijmegen - Radboud University Medical Center, Zuyderland Medical Centre, University Medical Center Utrecht, Elisabeth-Tweesteden Hospital, Medisch Spectrum Twente, Leiden University Medical Center, Isala Zwolle, VU University Amsterdam, Radboud University Nijmegen - Radboud University Medical Center, Vrije Universiteit Brussel (VUB), Noordwest Ziekenhuisgroep, University Medical Center Utrecht, HOVON Foundation, HOVON Foundation, Netherlands Comprehensive Cancer Organisation, Pathology Friesland, Vrije Universiteit Brussel (VUB), HOVON Foundation, University of Amsterdam, University of Groningen - University Medical Center Groningen and Maastricht University