KLF4 and meningioma: A prominent molecular meningioma classification separates tumors into 3 subtypes: Type A meningiomas with TRAF7, KLF4, and/or AKT serine/threonine kinase 1 (AKT1) missense mutations and without significant chromosomal copy number alteration; type B meningiomas primarily distinguished by NF2 loss; and type C meningiomas with biallelic NF2 inactivation plus loss of chromosome 1p (13, 14).