assertion retraction graph subject predicate object datatype annotation 1 0 graph DOID:4897 IAO:0000115 A bile duct cancer that has_material_basis_in abnormally proliferating cells derives_from epithelial cells. xsd:string "{""dce:type"":[{""datatype"":""_IRI"",""meta"":""owl:Axiom"",""object"":""obo:ECO_0007637""}],""oio:hasDbXref"":[{""datatype"":""xsd:string"",""meta"":""owl:Axiom"",""object"":""url:http://www.cancer.org/docroot/cri/content/cri_2_4_1x_what_is_bile_duct_cancer_69.asp""}]}"