HPSE and urinary bladder cancer: ciRS-7 negatively regulates bladder cancer proliferation by activating p21 [4]; hypoxia elevates circELP3 to promote bladder cancer progression and drug resistance [5]; the circular RNA CEP128 promotes bladder cancer cell propagation and migration by regulating MAPK signaling [5]; and circHIPK3 decreases lung metastasis through suppressing heparanase expression in bladder cancer [6].