1University of California, Comprehensive Cancer Center San Francisco, San Francisco, CA 94143, USA
2Prostate Cancer Program at the Kimmel Cancer Center at Johns Hopkins, Baltimore, MD 21231, USA
3Cell Genesys, Inc., Division of Clinical Research, South San Francisco, CA 94080, USA
4Department of Medical Oncology, University of Wisconsin, WI 53705, USA
5Department of Pharmacology, Oxford University, OX2 6DP Oxford, UK