In view of the downregulation of CD40 expression in cisplatin-resistant bladder cancer cells after NPM1 silencing, CD40 can be related to the survival, growth, and prognosis of tumors and reflects the changes of the NF-kappa B pathway related to NPM1, which indicates CD40 could be used as a biomarker to monitor the progression of cisplatin-resistant bladder cancer. The gene discussed is CD40; the disease is urinary bladder cancer.