IDH1 and malignant glioma: These results are striking since the proposal of maximal resection plus the watch-and-wait approach was applied to actual malignant gliomas with satisfying reported outcomes.32,33 A retrospective study, including 201 patients with a grade 2 (n = 131) or 3 (n = 70) oligodendroglioma, IDH-mutant and 1p/19q-codeleted according to the 2021 WHO classification, assessed the impact of early postoperative treatment and watch-and-wait approach.34 They reported that the early postoperative oncological treatment and the grade of malignancy were not associated with PFS.34