CCND1 and urinary bladder cancer: After knocking down the expression level of circGLIS3, the expression of Cyclin D1 considerably decreased, while the expression of Cyclin E, Cyclin A, and Cyclin B did not change significantly, suggesting that circGLIS3 may affect cell cycle changes by regulating the expression of Cyclin D1, thereby promoting bladder cancer cell proliferation (Fig. 4d–f).