The document discusses data integration strategies used by STRING, a database of known and predicted protein-protein interactions. STRING combines interaction data from numerous sources like experimental repositories, curated databases, text mining, and computational prediction methods. It maps identifiers across different databases, assigns confidence scores to interactions, and provides an interactive web interface for users to access and explore the integrated interaction network. External groups can contribute additional interaction data to STRING by hosting their own public data servers or providing data files in specified formats.