The STRING database (Search Tool for the Retrieval of Interacting Genes/Proteins) provides a comprehensive resource for characterizing protein-protein interactions, including both direct (physical) and indirect (functional) associations. Version 10.0 of STRING covers over 2000 organisms and introduces novel algorithms for transferring interaction information between organisms. Key improvements include hierarchical and self-consistent orthology annotations, a redesigned prediction pipeline for co-expression data, an API interface for the R computing environment, and enhanced statistical analysis for enrichment tests in user-provided networks. The database integrates curated experimental data, computational predictions, and orthologous group information, offering a robust framework for understanding protein functions and their interactions across the tree of life.The STRING database (Search Tool for the Retrieval of Interacting Genes/Proteins) provides a comprehensive resource for characterizing protein-protein interactions, including both direct (physical) and indirect (functional) associations. Version 10.0 of STRING covers over 2000 organisms and introduces novel algorithms for transferring interaction information between organisms. Key improvements include hierarchical and self-consistent orthology annotations, a redesigned prediction pipeline for co-expression data, an API interface for the R computing environment, and enhanced statistical analysis for enrichment tests in user-provided networks. The database integrates curated experimental data, computational predictions, and orthologous group information, offering a robust framework for understanding protein functions and their interactions across the tree of life.