SPEN and anaplastic astrocytoma: The most frequently mutated genes in the five patients diagnosed with anaplastic astrocytoma were IDH1 (40%), TP53 (40%), CCN2 (40%), KEAP1 (40%), KIT (40%), MAF (40%), PDGFRA (40%), SPEN (40%), TERT (40%), and TYRO3 (40%).