assertion retraction graph subject predicate object datatype annotation 1 0 graph DOID:4206 IAO:0000115 A brain stem cancer characterized by mass lesion of the brainstem in childhood, associated cranial nerve nuclei and long tracts, has_material_basis_in abnormally proliferating cells. xsd:string "{""dce:type"":[{""datatype"":""_IRI"",""meta"":""owl:Axiom"",""object"":""obo:ECO_0007636""}],""oio:hasDbXref"":[{""datatype"":""xsd:string"",""meta"":""owl:Axiom"",""object"":""url:https://ncit.nci.nih.gov/ncitbrowser/ConceptReport.jsp?dictionary=NCI_Thesaurus&version=16.12d&ns=NCI_Thesaurus&code=C5969""}]}"