STAT3 and hepatocellular carcinoma: Human HCC cell lines HepG2 and Hep3B cells were transfected with pcDNA3.1(+)-EGFP-STAT3, STAT3 siRNA and HK2 siRNA, respectively, or treated with rapamycin, an inhibitor of mammalian target of rapamycin (mTOR), and the effects on STAT3 and HK2 expression and cell glycolysis were determined.