Previously, Sturm et al. showed that epigenetic silencing of FOXG1 was characteristic of diffuse midline gliomas that are H3 K27M-mutant and located in the brainstem or thalamus, and that this type of glioma has a distinct cell of origin characterized by OLIG1+, OLIG2+, and FOXG1− [48]. This evidence concerns the gene OLIG1 and diffuse midline glioma.