HDAC9 and lung cancer: In conclusion, our findings show that HTPB is a novel pan-HDAC inhibitor that exhibits antitumor and antimetastatic activities in lung cancer cells but not in normal lung cells in cell and xenograft models, which involves not only histone acetylation-dependent activation of gene transcription, but also activation of intrinsic apoptotic pathways and down-regulation of integrin-β1/FAK/MMP/RhoA/F-actin motility control pathway.