In vivo tumor follow-up by CT showed that AAV9-Tert treated mice showed the same number of mice affected with tumors as well as the same number of tumors per mouse and the same tumor area as the AAV9-Null treated mice and the untreated control group both in the “pre-treatment” and “simultaneous treatment” experimental settings (Fig 1C–1I). Interestingly, mice pre-treated with AAV9-Tert-DN vectors before oncogene activation (“pre-treatment group”), showed a significant decrease in the percentage of mice developing tumors at 32 weeks post-oncogene activation (Fig 1C). The gene discussed is TERT; the disease is neoplasm.