The latest CNS WHO classification has not changed the criteria for diagnosing atypical meningiomas; however, for the first time, specific genetic alterations have been included in the grading, such as TERT promoter (pTERT) mutations and/or CDKN2A/B homozygous deletions (HDs), which are associated with meningioma recurrence and progression [12,69,75,76,77,78,79]. This evidence concerns the gene CDKN2A and meningioma.