TP53 and glioblastoma: Beginning with the examination of the hydroxamate derivative compounds, SAHA (vorinostat) has been shown in vitro to inhibit cell proliferation in glioblastoma cell lines independent of their p53 status, leading to an accumulation of cells arrested in the G2/M phase of the cell cycle, increased expression of anti-proliferative genes, and decreased levels of pro-growth genes[67].