Although often studied and even used in everyday diagnostics of meningiomas, the prognostic significance of the Ki67 index remains poorly defined.9,29,30 The Ki67 index significantly increases from BM through AM to MM, but there is a considerable overlap between different grades.9,29,31 In a series of primary meningiomas of all three grades, Perry et al. reported a Ki67 index ≥ 4.2% associated with the decreased recurrence-free survival in univariate but not in multivariate analysis.29 Here, MKI67 is linked to meningioma.