Immunohistochemical staining revealed that the tumor cells were positive for GFAP, oligodendrocyte transcription factor 2, histone H3K27M mutant protein, alpha-thalassemia/mental retardation syndrome X, S-100 and Vimentin, but negative for IDH1 R132H, Syn and NeuN. The gene discussed is OLIG2; the disease is neoplasm.