According to the 2021 WHO classification, the tumors were classified as “astrocytoma, IDH-mutant, grade 2;” “astrocytoma, IDH-mutant, grade 3;” and “astrocytoma, IDH-mutant, grade 4” in 21, 3, and 9 patients, respectively. Here, IDH1 is linked to astrocytoma (excluding glioblastoma).