AKT1 and meningioma: Likewise, there are associations between some mutations seen and with specific histopathologic variants of meningioma, for example NF2 in fibroblastic and transitional meningiomas (68, 69), KLF4 and TRAF7 in secretory meningiomas (81), and AKT1 mutations in grade I meningothelial meningiomas particularly of the base of the skull and spine (82).