The following DataNodes have no identifier: 1
http://classic.wikipathways.org/instance/WP4146_r107552 http://rdf.wikipathways.org/Pathway/WP4146_r107552/DataNode/dbb52 (Cd52)
More details at https://www.wikipathways.org/WikiPathwaysCurator/DataNodesTests/dataNodesWithoutIdentifier