International Protein Index
- accession numbers from a variety of bioinformatics databases to be mapped
- a complete set of proteins for a species i.e. a reference set
IPI was launched in 2001 by the European Bioinformatics Institute (EBI) when databases cataloguing human genes varied greatly and had few links between them. Since then much more data has been produced giving a more complete picture and databases have collaborated to synchronize data. Currently many model organisms have a reference set of genes/proteins which are catalogued in Ensembl/UniProt respectively, as well as other species specific databases.
Due to advances in data organisation, IPI was retired in 2011. EBI advised users of its services to employ UniProtKB accession numbers as their protein identifiers.