SIRT1 and neoplasm: Several studies have shown that SIRT1 protein levels are lower in lesion tissues than in adjacent tumor tissues or normal tissues of patients with cancer.365–367 This phenomenon is also observed in autoimmune disorders, which indicates that SIRT1 plays important roles in regulating cell migration and invasion.368 SIRT1, as a deacetylase, influences the biological functions of proteins via regulating protein deacetylation, such as deacetylation of Beclin-1.