XRCC6 and medulloblastoma: Indeed, it has been reported a correlation between resistance to chemo- and/or radiotherapy and a high Ku70–Ku86 expression/activity [80–82] Moreover, some reports have shown the modulation of Ku70 acetylation status and Ku70-Bax interaction, by means of HDAC inhibitors, both effects inducing chemosensitivity in medulloblastoma and neuroblastoma cells [55, 73, 83].