OLIG2 and neoplasm: Tumor cells were positive for glial fibrillary acidic protein (GFAP), oligodendrocyte lineage transcription factor 2 (Olig-2), tumor suppressor protein 53 (p53), and focally for synaptophysin but negative for neuronal nuclei antigen (NeuN) and alpha-thalassaemia/mental-retardation X-linked (ATRX).