Phenylbutyrate, another short-chain fatty acid HDAC inhibitor, has demonstrated its efficacy (like TSA) through increasing the expression of GFAP in human glioblastoma cells in culture as well as redistributing intracellular GFAP thereby enhancing gap junction communication between tumor cells through upregulation of the protein connexin 43[68,70]. The gene discussed is HDAC9; the disease is glioblastoma.