IDH1 and anaplastic astrocytoma: Among the remaining 23 cases (11 %) with ATRX loss and IDH wild type (wt) status (10 anaplastic astrocytoma, 13 glioblastoma), 7 cases had a H3F3A p.G34R mutation (3 %, Fig. 2c) and 2 cases had a H3F3A p.K27M mutation (1 %).