The following DataNodes have no identifier: 1
http://classic.wikipathways.org/instance/WP3657_r127709 http://rdf.wikipathways.org/Pathway/WP3657_r127709/DataNode/fd8ae (HSC quiescence)
More details at https://www.wikipathways.org/WikiPathwaysCurator/DataNodesTests/dataNodesWithoutIdentifier