In studies using groups of four or five mice each, administration of five intratracheal doses of DP3-p53 (2 μg or 8 μg DNA per dose) on days 4–20 after intratracheal tumor inoculation significantly inhibited lung tumor formation and increased by about twofold the survival of mice carrying H358 or H322 endobronchial tumor cells, in contrast to untreated mice and mice treated with the DP3-empty vector [42]. The gene discussed is TP53; the disease is neoplasm.