assertion retraction graph subject predicate object datatype annotation 1 0 graph DOID:4054 IAO:0000115 A prostate cancer that is located_in the prostate. xsd:string "{""oio:hasDbXref"":[{""datatype"":""xsd:string"",""meta"":""owl:Axiom"",""object"":""url:https://radiopaedia.org/articles/prostate-sarcoma""}]}"