The following DataNodes have no identifier: 1
http://classic.wikipathways.org/instance/WP4627_r129311 http://rdf.wikipathways.org/Pathway/WP4627_r129311/DataNode/c56df (Not yet identified acetylated amino acid residue)
More details at https://www.wikipathways.org/WikiPathwaysCurator/DataNodesTests/dataNodesWithoutIdentifier