In a previous study, we could show that inhibition of NAMPT activity via its specific inhibitor FK866 induces energy stress leading to apoptosis in HCC cell lines which was associated with adenosine monophosphate (AMP)-activated protein kinase (AMPK)-mediated inhibition of the mechanistic target of rapamycin (mTOR) signaling [9]. Here, MTOR is linked to hepatocellular carcinoma.