A Sirt1−/− mouse model indicated that SIRT1 prevented the induction of prostate intraepithelial neoplasia and inhibits reactive oxygen species production by promoting mitophagy and a low level of SIRT1 has been associated with decreased recurrence-free survival in prostate cancer, which implies that SIRT1 could have a defensive role against cancer32. The gene discussed is SIRT1; the disease is prostate intraepithelial neoplasia.