SIRT1 and neoplasm: Moreover, inconsistent with our finding that stronger SIRT1 expression was coupled with a higher metastatic rate, another study reported that SIRT1 was overexpressed in 25% of stage I/II/III colorectal adenocarcinomas, but was rarely found in advanced stage IV tumours; meanwhile, 30% of carcinomas showed lower than normal SIRT1 expression [29].