assertion retraction graph subject predicate object datatype annotation 1 0 graph DOID:13109 IAO:0000115 A bladder benign neoplasm that derives_from smooth muscle cells. 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/pmc/articles/PMC5532898/""}]}"