The following DataNodes have no identifier: 1
http://classic.wikipathways.org/instance/WP3925_r123124 http://rdf.wikipathways.org/Pathway/WP3925_r123124/DataNode/a2573 (Gst)
More details at https://www.wikipathways.org/WikiPathwaysCurator/DataNodesTests/dataNodesWithoutIdentifier