Several previously described activities of SIRT1, particularly those related to modulation of p53 activity [9], [10], c-myc [51], [52], [53], [54], canonical Wnt signaling [55] and epigenetic control [24], may account for the reduction in tumor size we observed in the intestines of APC+/min SIRT1−/− mice. This evidence concerns the gene TP53 and neoplasm.