The remainder are grade 2 or 3, with a higher tendency to recur.84 These tumours are mostly sporadic, however patients who had previous exposure to cranial radiation (radiation-induced meningioma), and patients with NF2-schwannomatosis (NF2-SWN) have a tendency to develop more aggressive and multiple tumours.85,86 Sporadic tumours have a variety of recurrent oncogenic mutations; most are NF2-mutated, but others, which are mutually exclusive with NF2, include TRAF7, AKT1, KLF4, SMO and PIK3CA.87 The gene discussed is KLF4; the disease is neoplasm.