HDAC9 and ovarian cancer: Although treatment of HDAC inhibitor (TSA) or EZH2 inhibitor (GSK343) alone did not result in any significant re-expression of ABCA1, treatment of demethylating agent, 5aza, alone resulted in a robust re-expression of ABCA1 in CP70 ovarian cancers, suggesting that DNA methylation is responsible for the suppression of ABCA1 in CP70 cells (Figure 1B).