About the Authors Ian Tannock, MD, PhD, Professor of Medical Oncology and Hematology Princess Margaret Hospital University of Toronto Toronto, Ontario, CanadaRichard Hill, PhD Senior Scientist, Division of Experimental Therapeutics Professor of Medical Biophysics University of Toronto Toronto, Ontario, CanadaRobert Bristow, MD, PhD Clinician-Scientist, Radiation Medicine Program Princess Margaret Hospital University of Toronto Toronto, Ontario, CanadaLea Harrington, PhD Senior Scientist, Division of Cellular and Molecular Biology University of Toronto Toronto, Ontario, Canada