EZH2 and glioblastoma: For example, phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) acts as a signaling enzyme for cell proliferation and intracellular trafficking in GBM, and the enhancer of zeste homolog 2 (EZH2) acts as a histone methylator that causes transcriptional repression to inhibit tumor suppressor genes in many cancers.