The Database of Interacting Proteins (DIP) is an online resource that integrates experimental evidence on protein-protein interactions. Since its initial development, DIP has expanded to include over 18,500 distinct binary protein-protein interactions and references from more than 2,500 research articles. The database uses a relational structure with key tables for proteins, sources, and evidence, and additional tables for interactions and multi-protein complexes. Quality assessment methods, including the PVM and EPR methods, are employed to identify a reliable core subset of interactions. DIP also integrates data from the Protein Data Bank to describe atomic-level interactions. The database offers both interactive and batch access, supporting various data formats, including MIF, for data exchange. Future developments will focus on integrating additional data sources and improving quality assessment to better understand protein interaction networks.The Database of Interacting Proteins (DIP) is an online resource that integrates experimental evidence on protein-protein interactions. Since its initial development, DIP has expanded to include over 18,500 distinct binary protein-protein interactions and references from more than 2,500 research articles. The database uses a relational structure with key tables for proteins, sources, and evidence, and additional tables for interactions and multi-protein complexes. Quality assessment methods, including the PVM and EPR methods, are employed to identify a reliable core subset of interactions. DIP also integrates data from the Protein Data Bank to describe atomic-level interactions. The database offers both interactive and batch access, supporting various data formats, including MIF, for data exchange. Future developments will focus on integrating additional data sources and improving quality assessment to better understand protein interaction networks.