The cancer preventive activity of p53 could also be mediated by other pathways; for example, it has been shown that rapamycin, a known inhibitor of mTOR pathway, decreases the number of tumors originated in p53−/− or p53+/− mice [5, 6], suggesting a causative role of mTOR inhibition in tumor prevention. The gene discussed is TP53; the disease is neoplasm.