Since various HDAC inhibitors have been reported to induce cell death in medulloblastoma cell lines [19], we used TSA, a pan-HDAC inhibitor at relatively low concentrations (10 nM∼100 nM) that reduced SAG-induced HDAC activation close to levels of unstimulated (differentiating) CGP cells but did not induce cell death (Fig. 5A). This evidence concerns the gene HDAC9 and medulloblastoma.