The following DataNodes have no identifier: 1
http://classic.wikipathways.org/instance/WP5336_r126593 http://rdf.wikipathways.org/Pathway/WP5336_r126593/DataNode/fb6c2 (TRIF)
More details at https://www.wikipathways.org/WikiPathwaysCurator/DataNodesTests/dataNodesWithoutIdentifier