TERT and meningioma: In particular, hotspot mutations (C228T and C250T) in the TERT promoter were detected in 20% of WHO grade 3 meningiomas compared to 1.7% and 5.7% of grade 1 and 2 meningiomas, respectively [1,40], and in 6.4% in a large cohort of meningiomas [30].