The following DataNodes have no identifier: 1
http://classic.wikipathways.org/instance/WP3165_r117564 http://rdf.wikipathways.org/Pathway/WP3165_r117564/DataNode/fd179 (OCT2)
More details at https://www.wikipathways.org/WikiPathwaysCurator/DataNodesTests/dataNodesWithoutIdentifier