The following DataNodes have no identifier: 1
http://classic.wikipathways.org/instance/WP2864_r108133 http://rdf.wikipathways.org/Pathway/WP2864_r108133/DataNode/fcb5a (PPP2GB)
More details at https://www.wikipathways.org/WikiPathwaysCurator/DataNodesTests/dataNodesWithoutIdentifier