The following DataNodes have no identifier: 1
http://classic.wikipathways.org/instance/WP1016_r117633 http://rdf.wikipathways.org/Pathway/WP1016_r117633/DataNode/fd4 (TCF-1/LEF)
More details at https://www.wikipathways.org/WikiPathwaysCurator/DataNodesTests/dataNodesWithoutIdentifier