assertion  retraction  graph  subject             predicate        object              datatype  annotation
1          0           graph  obo:UBERON_0010371  rdfs:subClassOf  obo:UBERON_0004121  _IRI      
1          0           graph  obo:UBERON_0002097  rdfs:subClassOf  obo:UBERON_0004121  _IRI      
1          0           graph  obo:UBERON_0001768  rdfs:subClassOf  obo:UBERON_0004121  _IRI