In the present study, our results further indicated that the synthetic peptide conjugated with R11 (R11-p53C) was efficiently and preferentially delivered into bladder cancer cells, resulting in the inhibition of tumor growth regardless of the status of p53. More interestingly, this inhibition manifested as a high efficiency in both primary and metastatic tumor models without a significant toxicity. This evidence concerns the gene TP53 and urinary bladder carcinoma.