PIK3CA and meningioma: Notwithstanding, this subclass also contained 14 WHO grade 2 meningiomas (8 AKT1, 5 PIK3CA, and 1 SMO case), and a subset of these higher grade cases harbored additional genomic alterations such as TERTp mutation (one AKT1-mutant meningioma), TP53 mutation (one PIK3CA-mutant case), PTEN alterations (2 meningiomas with an AKT1 mutation), and CDKN2A 2 copy loss (1 AKT1 case; 1 PIK3CA case).