1. Department of Urology, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi 710061, P.R. China
2. Department of Pathology,The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi 710061, P.R. China
3. Department of Urology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA