APC and neoplasm: While SIRT1 was reported to suppress intestinal tumorigenesis in the APCmin/+ mouse model by deacetylating and inactivating β-catenin [19], a recent study revealed that there was no difference in tumor development when APC+/min mice crossed with SIRT1-null mice, and that average polyp size was slightly smaller in SIRT1-null APC+/min mice [38].