Study design. Samples of urothelial tissues and urine collected at the indicated participating centers and distributed for identification of UC-specific DNA-methylation sites (First step) and validation of diagnostic accuracy (Second and Third steps) as indicated. N: normal urothelia, CN: corresponding normal-appearing tissue adjacent to tumor from UC patient, T: tumor samples from UC patients; NU: urine from normal participants, TU: urine from UC patients treated by transuretheral resection; PSQ: pyrosequencing. Institution 1: Department of Urology, Norris Comprehensive Cancer Center, University of Southern California. Institution 2: Urology Division, National Cancer Center Hospital, Tokyo. Institution 3: Department of Urology, Nara Medical University. Institution 4: Department of Urology, Tochigi Cancer Center Hospital.