Another example of integration with external resources is AOP-Wiki, a data source for sharing information on adverse outcome pathways which is available in RDF format (AOP-Wiki RDF) through a public SPARQL endpoint . The objective of this integration is to identify potential adverse outcomes associated with nanomaterials, as reported in the NanoLinks-KG knowledge graph, by leveraging the AOP-Wiki SPARQL endpoint. Since NanoLinks-KG does not directly link nanomaterials to Adverse Outcome Pathways (AOPs), we utilize an additional SPARQL endpoint developed by JPM van Rijn et al. in their previous work . In that study, nanomaterials were manually annotated with related key events based on a comprehensive literature review, establishing indirect connections. Using a federated SPARQL query, it becomes possible to link nanomaterials to key events through this endpoint. To map these key events to their corresponding adverse outcome pathways, we further integrate with the AOP-Wiki SPARQL endpoint, extracting the relevant adverse outcomes and their titles. The SPARQL query presented in Listing 4 demonstrates this federated querying approach, returning nanomaterial types, titles of associated adverse outcomes, and the count of key events associated with both the nanomaterials and the adverse outcome pathway. The query results are provided in Supplementary file S2 covering nine unique material types and 84 unique adverse outcomes. ORDER BY ? m a t e r i a l T y p e ? keyEventCount Listing 4 A SPARQL query example that uses federated querying to integrate NanoLinks-KG with AOP-Wiki SPARQL endpoint. The query uses two services for federated queries. The first serives is the SPARQL endpoint of JPM van Rijn et al. . It is queried to link material type from NanoLinks-KG to key events. The second service is AOP-Wiki SPARQL endpoint where the obtained key events fromt the first service are further linked to adverse outcomes through adverse outcome pathways. The results of the query return nanomaterial type and title of the adverse outcome and the number of the key events involved in the related adverse outcome pathway