For example, a HDAC inhibitor (trichostatin A), a PI3K inhibitor (LY294002), natural compounds, such as resveretrol and chrysin, and several drugs, including phenothiazines (trifluoperazine and thioridazine), monoamine oxidase A (MAO-A) inhibitor (harmine), and a colchicine analog (trimethylcolchicinic acid), were all found to produce an opposite gene expression profile in MCF-7 or the prostate cancer cell line, PC3. This evidence concerns the gene HDAC9 and prostate cancer.