1. Hospital Universitario Virgen del Rocio, Instituto de Biomedicina de Sevilla (center affiliated with the Red Temática de Investigación Cooperativa en Cancer, Instituto Carlos III, Spanish Ministry of Science and Innovation), Sevilla, Spain;
2. Hospital Universitario Marqués de Valdecilla, Santander, Spain;
3. Hospital Clinic i Provincial, Barcelona, Spain;
4. Centre Hospitalier de l'Université de Montréal, Montréal, Quebec, Canada;
5. Princess Margaret Hospital and University of Toronto, Toronto, Ontario, Canada;
6. Department of Hematology and Medical Oncology, Biomedical Research Institute INCLIVA, University of Valencia, Valencia, Spain;
7. The Ottawa Hospital, Ottawa, Ontario, Canada;
8. ImClone Systems (a wholly-owned subsidiary of Eli Lilly and Company), Bridgewater, New Jersey, USA;
9. Vall d'Hebron University Hospital and Institute of Oncology, Universitat Autònoma de Barcelona (center affiliated with the Red Temática de Investigación Cooperativa en Cancer, Instituto Carlos III, Spanish Ministry of Science and Innovation), Barcelona, Spain