assertion retraction graph subject predicate object datatype annotation 1 0 graph DOID:4527 IAO:0000115 An ovary sarcoma that is a malignant vascular tumor that derives_from blood vessels. xsd:string "{""dce:type"":[{""datatype"":""_IRI"",""meta"":""owl:Axiom"",""object"":""obo:ECO_0007645""}],""oio:hasDbXref"":[{""datatype"":""xsd:string"",""meta"":""owl:Axiom"",""object"":""url:https://www.ncbi.nlm.nih.gov/pubmed/24520828""}]}"