TP53 and neoplasm: Compared to the U87 control tumors, only 50 μM TMZ significantly reduced the number of p53-positive cells in the U87 tumor; T98G-50 μM TMZ tumors expressed a significantly decreased p53-positive cell number, while the frequency of p53-positive T98G cells in the tumor did not differ between 2 mM VPA–3 mM NaDCA-treated and control groups.