The therapeutic potency of the vectors was tested by direct intratumoral injection of 25 μg of the DTA expression vectors (H19-DTA, P4-DTA, or H19-DTA-P4-DTA), or of the control vectors (H19-Luc, P4-Luc, or H19-Luc-P4-Luc) into each heterotopic bladder tumor. This evidence concerns the gene H19 and urinary bladder neoplasm.