OLIG2 and neoplasm: Immunohistochemistry revealed the tumor cells to be vimentin positive, glial fibrillary acidic protein positive, Olig2 positive, IDH1-R132H negative, ATRX retained, P53 positive, MIB1 labeling of 70%-80%, synaptophysin positive in undifferentiated cells, epithelial membrane antigen negative, L1CAM negative, leukocyte common antigen negative, BCOR negative, MSH2 retained, MSH6 retained, and MLH1 retained, and PMS2 showed loss of nuclear expression in tumor cells and endothelium.