MKI67 and astrocytoma (excluding glioblastoma): The proportion of Ki-67-positive nuclei was significantly increased (P < 0.0001) in H3 K27M-mutant astrocytomas; a total of 28/35 H3 K27M-mutant cases had a high percentage of Ki-67-positive nuclei (≥ 10%), while only 18/48 H3-wildtype cases had a high percentage of Ki-67-positive nuclei.