Reply to Erfan Ayubi and Saeid Safiri's Letter to the Editor re: Sungmin Woo, Chong Hyun Suh, Sang Youn Kim, Jeong Yeon Cho, Seung Hyup Kim. Diagnostic Performance of Prostate Imaging Reporting and Data System Version 2 for Detection of Prostate Cancer: A Systematic Review and Diagnostic Meta-analysis. Eur Urol 2017;72:177-88.