Those NANOG-positive cells seem to be only 1% in low-grade, and 2% in grade II/III meningiomas; nonetheless, in this study and in other literature, they have demonstrated their remarkable impact on tumorigenesis and progression in human meningiomas and high-grade gliomas, being correlated with the overall clinical and surgical prognosis [12,31,32,33]. The gene discussed is NANOG; the disease is glioma.