_:vb50954007 . _:vb50954007 . _:vb50954007 "url:https://en.wikipedia.org/wiki/Ependymoma"^^ . _:vb50954007 . _:vb50954007 "url:https://en.wikipedia.org/wiki/Ependyma"^^ . _:vb50954007 . _:vb50954007 "A high grade ependymoma that is characterized by abnormal growth of the neuroepithelial lining of the ventricular system, has_material_basis_in abnormally proliferating cells derives_from ependymal cells."^^ . _:vb50954007 .