Males absent on the first (MOF) is a histone acetyltransferase belongs to the MYST (MOZ, Ybf2/Sas3, Sas2 and TIP60) family. In mammals, MOF plays critical roles in transcription activation by acetylating histone H4K16, a prevalent mark associated with chromatin decondensation. MOF can also acetylate transcription factor p53 on K120, which is important for activation of pro-apoptotic genes; and TIP5, the largest subunit of NoRC, on K633. However, the role of hMOF in hepatocellular carcinoma remains unknown. Here we find that the expression of hMOF is significantly down-regulated in human hepatocellular carcinoma and cell lines. Furthermore, our survival analysis indicates that low hMOF expression predicts poor overall and disease-free survival. We demonstrate that hMOF knockdown promotes hepatocellular carcinoma growth in vitro and in vivo, while hMOF overexpression reduces hepatocellular carcinoma growth in vitro and in vivo. Mechanically, we show that hMOF regulates the expression of SIRT6 and its downstream genes. In summary, our findings demonstrate that hMOF participates in human hepatocellular carcinoma by targeting SIRT6, and hMOF activators may serve as potential drug candidates for hepatocellular carcinoma therapy. (C) 2014 Elsevier Inc. All rights reserved.