In conclusion, our in vitro and in vivo results validate the assumption that CBX7 is a tumor suppressor of gliomas. Moreover, CBX7 is a potential and novel prognostic biomarker in glioma patients. In addition to showing CBX7-induced phenotypic changes, we also found that CBX7 silences CCNE1 via the combination of CCNE1 promoter and the recruitment of HDAC2.