1. Department of Urology, University of California San Francisco, San Francisco, California, USA.
2. School of Medicine, University of California San Francisco, San Francisco, California, USA.
3. College of Medicine, University of Central Florida, Orlando, Florida, USA.
4. Division of Biostatistics, University of California San Francisco, San Francisco, California, USA.
5. Department of Urology, Duke University, Durham, North Carolina, USA.