The interaction between cyclin E and CDK2 plays an essential role in the G1/S phase transition via phosphorylation of p27Kip. Misregulation of cyclin E/CDK2 complex occurs in various types of tumors and leads to uncontrolled cell growth [38–40]. Thus, the CBX7-induced suppression of CCNE1, which encodes cyclin E1, contributed to the attenuation of glioma progression. Considering the complexity of phosphorylated proteins downstream of the cyclin E/CDK2 complex, further investigation is warranted. Furthermore, the interaction between CBX7 and other PcG proteins such as EZH2, CBX6 and CBX8 will require additional clarification.