Treatment of murine and human PDX medulloblastoma cell lines with the pan-HDAC inhibitor Panobinostat lead to significant decreases in cell viability, with the lowest IC50 (14.4nM) seen in Grp3 MYC-driven PDX cells, and a marginally higher IC50 (25.27nM) in Grp4 MYCN-driven PDX (152). This evidence concerns the gene HDAC9 and medulloblastoma.