UBE2E3 and urinary bladder cancer: cir-ITCH is a well-known tumor-suppressing circRNA generated from several exons of itchy E3 ubiquitin protein ligase (ITCH), which is downregulated in colorectal cancer [8], lung cancer [9], esophageal squamous cell carcinoma [10], and bladder cancer [11], and serves as a sponge for certain miRNAs, including miR-17 and miR-214 [11, 31].