In the present study, we focused on the role of circ_VANGL1 and its effects on cell growth, apoptosis, and the doxorubicin sensitivity in bladder cancer in vitro and in vivo through molecular and functional experiments and revealed that circ_VANGL1 served as a sponger of miR-145-5p to regulate SOX4 expression. The gene discussed is SOX4; the disease is urinary bladder cancer.