1. The Medical College of Qingdao University, Qingdao 266071, China
2. Department of Andrology, The Affiliated Hospital of Qingdao University, Qingdao 266003, China
3. Department of Clinical Laboratory, The Affiliated Hospital of Qingdao University,Qingdao 266003, China
4. Department of Urology, The Affiliated Hospital of Qingdao University, Qingdao 266003, China
5. Department of Oncology, The Affiliated Hospital of Qingdao University, Qingdao 266003, China