The following DataNodes have no identifier: 4
http://classic.wikipathways.org/instance/WP1176_r117467 http://rdf.wikipathways.org/Pathway/WP1176_r117467/DataNode/c49 (BSG)
http://classic.wikipathways.org/instance/WP1176_r117467 http://rdf.wikipathways.org/Pathway/WP1176_r117467/DataNode/bbe (MMP10)
http://classic.wikipathways.org/instance/WP1176_r117467 http://rdf.wikipathways.org/Pathway/WP1176_r117467/DataNode/efd (MMP23A)
http://classic.wikipathways.org/instance/WP1176_r117467 http://rdf.wikipathways.org/Pathway/WP1176_r117467/DataNode/ff7 (TIMP4)
More details at https://www.wikipathways.org/WikiPathwaysCurator/DataNodesTests/dataNodesWithoutIdentifier