USP18 and urinary bladder cancer: Importantly, previous studies have reported that USP18 was upregulated in bladder cancer tissues and promoted the malignant cell phenotype of bladder cancer.[41, 42] Consistent with the above findings, we also found that USP18 could restore the tumor‐suppressing function of BCCE4[A], indicating that USP18 plays an oncogenic role in bladder cancer.