IDH1 and astrocytoma (excluding glioblastoma): A recent study based on patients included in the EORTC trials 26053 (CATNON) and 22033–26033 supported a prognostic role of mitotic activity and reported that a cut-off of two mitoses per ten microscopic high power fields was linked to significantly longer PFS and marginally longer OS in patients with IDH-mutant astrocytoma without homozygous CDKN2A/CDKN2B deletion [28].