Our study showed that knockdown of these p53 mutants by small interfering (si)RNA not only induced cell cycle arrest and cell apoptosis in T24 and 5637 bladder cancer cell lines, but also cooperated with cisplatin in the inhibition of these cancer cells, suggesting that siRNAs may serve as alternative agents for the treatment of bladder cancer by targeting mutant p53. The gene discussed is TP53; the disease is cancer.