The following DataNodes have no identifier: 1
http://classic.wikipathways.org/instance/WP4259_r128548 http://rdf.wikipathways.org/Pathway/WP4259_r128548/DataNode/bb389 (p-amino-benzoyl-polyglutamate)
More details at https://www.wikipathways.org/WikiPathwaysCurator/DataNodesTests/dataNodesWithoutIdentifier