HDAC9 and cancer: Western blot analysis of acetylated histone 3 lysine 9 (Ac-H3K9) and beta-catenin, which is the direct target of GSK3B, protein levels re-probed for glyceraldehyde 3-phosphate dehydrogenase (GAPDH) showed that treatment with 0.6 μM APCS-540 significantly inhibited HDAC and GSK3B pathways in both A2780 and A2780cis cancer cells compared to control (Supplementary Fig. S2A).