PVT1 and central nervous system cancer: qRT-PCR analysis demonstrated that PVT1 and EZH2 were expressed at higher levels in glioma tumor tissues and cell lines than normal brain tissues and HEB cells, and positively correlated with glioma malignancy (glioma grades, Figure 1A,B), which mean the higher the malignant grade of glioma, the higher the PVT1 and EZH2 expression level.