[1] Univ Pittsburgh Med Ctr UPMC, Pittsburgh, PA USA
[2] UPMC, Hillman Canc Ctr, Pittsburgh, PA USA
[3] UV UCC, IOB Quiron, Vall dHebron Hosp Campus & Inst Oncol VHIO, Barcelona, Spain
[4] Harvard Med Sch, Massachusetts Gen Hosp, Canc Ctr, Boston, MA USA
[5] Univ St Luc, Inst Roi Albert 2, Dept Med Oncol Clin, Brussels, Belgium
[6] Catholic Univ Louvain, Inst Rech Clin & Expt Pole MIRO, Brussels, Belgium
[7] Klinikum Harlaching, Klinikum Neuperlach, Dept Hematol & Oncol, Munich, Germany
[8] Queen Mary Univ London, Barts Canc Inst, London, England
[9] St Bartholomews Hosp, Gastrointestinal Canc Ctr, London, England
[10] Exelixis Inc, Alameda, CA USA
[11] UCLA, David Geffen Sch Med, Jonsson Comprehens Canc Ctr, Santa Monica, CA 90095 USA