The following DataNodes have no identifier: 2
http://classic.wikipathways.org/instance/WP3583_r117433 http://rdf.wikipathways.org/Pathway/WP3583_r117433/DataNode/d3e3c (GOX)
http://classic.wikipathways.org/instance/WP3583_r117433 http://rdf.wikipathways.org/Pathway/WP3583_r117433/DataNode/fa1d2 (P5P)
More details at https://www.wikipathways.org/WikiPathwaysCurator/DataNodesTests/dataNodesWithoutIdentifier