OLIG2 and ependymoma: Although there are strong arguments for consideration of these tumors as a specific type of glioma (typical glioma- and/or ependymoma-like features in combination with consistent expression of GFAP and OLIG2), the lack of a clear indication of a particular lineage and the small number of cases with sufficient material for a comprehensive histopathological evaluation suggest the provisionally use of the term “neuroepithelial” to describe these neoplasms.