SIRT1 and hepatocellular carcinoma: Moreover, a recent study in hepatocellular carcinoma (HCC) showed that the over-expression of SIRT1 promoted tumorigenesis and resistance to chemotherapeutical agent and sorafenib [19].however, the association between SIRT1 expression and the clinical characteristics, especially the responsiveness to chemotherapy and prognosis in NSCLC remain largely unknown.