After the primary directed network was constructed, other commonly used database identifiers (ChEBI and HMDB ) were added to the model as separate nodes, labeled ":Mapping". These identifier mapping nodes were connected with their counterpart Wikidata metabolite node through edges labeled as ":MappingInteractions". These nodes allow querying for old and new HMDB identifier types (making use of the BridgeDb framework directly from the RDF), and ChEBI with and without the prefix "CHEBI:".