MEG3 and glioma: Xu et al. revealed that the copy number variation (CNV) levels of MEG3 were positively associated with overall survival and progression-free survival compared to the wild-type in low-grade glioma [123]; Gao et al. revealed, using 63 patients with retinoblastoma, that hypermethylation of MEG3 promoter was highly associated with poor survival, further confirming that MEG3 expression level is negatively correlated with poor prognosis [128].