Furthermore, inhibition of EZH2 expression in glioma by siEZH2 or DZNep not only decreased the growth of glioma, but also delayed M2 macrophage polarization in a co-culture system of microglia and glioma cells and an in vivo experiment, which demonstrated the interaction between tumor cells and macrophages in the tumor microenvironment (5, 12). This evidence concerns the gene EZH2 and central nervous system cancer.