assertion retraction graph subject predicate object datatype annotation 1 0 graph DOID:5518 IAO:0000115 A penis carcinoma that has_material_basis_in squamous cells. xsd:string "{""dce:type"":[{""datatype"":""_IRI"",""meta"":""owl:Axiom"",""object"":""obo:ECO_0007638""}],""oio:hasDbXref"":[{""datatype"":""xsd:string"",""meta"":""owl:Axiom"",""object"":""url:http://en.wikipedia.org/wiki/Squamous-cell_carcinoma""}]}"