HDAC9 and hepatocellular carcinoma: However, in hepatocellular carcinoma (HCC) cells, PCAF suppresses Hh signaling by directly acetylating cytoplasmic GLI1 protein at lysine 518, preventing its nuclear translocation and promoter occupancy [66], whereas deacetylation of Gli1 and Gli2 by histone deacetylases (HDAC) promotes their transcriptional activation in medulloblastoma [67].