assertion retraction graph subject predicate object datatype annotation 1 0 graph DOID:176 IAO:0000115 An organ system cancer that located_in the heart and blood vessels. xsd:string "{""dce:type"":[{""datatype"":""_IRI"",""meta"":""owl:Axiom"",""object"":""obo:ECO_0007637""},{""datatype"":""_IRI"",""meta"":""owl:Axiom"",""object"":""obo:ECO_0007641""}],""oio:hasDbXref"":[{""datatype"":""xsd:string"",""meta"":""owl:Axiom"",""object"":""url:http://www.cancer.gov/dictionary?CdrID=44005""},{""datatype"":""xsd:string"",""meta"":""owl:Axiom"",""object"":""url:https://www.ncbi.nlm.nih.gov/books/NBK537144/""}]}"