D574 Nucleic Acids Research, 2007, Vol. 35, Database issue or gene names, UniProt keywords or identiﬁers of external databases: UniProtKB, PDB, Ensembl, FlyBase, SGD, WormBase, OMIM, HUGE, PubMed and Reactome. It is also possible to query species speciﬁc datasets (mammalian, Saccharomyces cerevisiae, Caemorhabaditis elegans, Droso- phila melanogaster, viruses). Finally, a sequence similarity search (BLAST) can also be performed to search for proteins which are homologous to the query protein. The query results are displayed in a table showing in the left frame a summary of the protein features reported in Uni- Prot and, in the right frame, the list of the interaction partners curated in MINT. The interactions can be displayed graphi- cally by an enhanced version of the ‘MINT viewer’, a Java applet derived from the applet Graph (http://java.sun.com). The viewer represents the interactions by lines (edges) and nodes (proteins), and assigns the nodes a size proportional to the protein’s molecular weight and a color which depends on the species. The graph displayed by the viewer can be expanded and edited interactively by moving or deleting nodes. Proteins linked to OMIM are now highlighted in red. In order to attribute a reliability index to the reported interactions, we have also assigned each interaction a conﬁ- dence level, based on the experimental detection method and experimental conditions. The results of the analysis performed in the MINT viewer can be captured in different formats ready for export: PSI1.0-XML, PSI2.5-XML, ﬂat- ﬁle, Osprey. MINT is now also complemented by HomoMINT (7), an inferred human protein interaction network where inter- actions discovered in model organisms (and collected in MINT) are mapped onto the corresponding human orthologs. Through the MINT web pages it is also possible to search the HomoMINT dataset for inferred interactions. A web service allows direct computational access so as to freely retrieve interaction networks in different formats: ﬂat-ﬁle, PSI1.0-XML, PSI2.5-XML. It is also possible to download speciﬁc subsets of the database based on the taxonomy of the interactors. ACKNOWLEDGEMENTS This work is supported by AIRC and by the European Union FP6 Interaction Proteome project and the ENFIN network of excellence. Funding to pay the Open Access publication charges for this article was provided by European Union FP6. Conflict of interest statement. None declared. REFERENCES 1. Hermjakob,H., Montecchi-Palazzi,L., Lewington,C., Mudali,S., Kerrien,S., Orchard,S., Vingron,M., Roechert,B., Roepstorff,P., Valencia,A. et al. (2004) IntAct: an open source molecular interaction database.. Nucleic Acids Res., 32, D452–D455. 2. Zanzoni,A., Montecchi-Palazzi,L., Quondam,M., Ausiello,G., Helmer-Citterich,M. and Cesareni,G. (2002) MINT: a Molecular INTeraction database. FEBS Lett., 513, 135–140. 3. Salwinski,L., Miller,C.S., Smith,A.J., Pettit,F.K., Bowie,J.U. and Eisenberg,D. (2004) The Database of Interacting Proteins: 2004 update. Nucleic Acids Res., 32, D449–D451. 4. Guldener,U., Munsterkotter,M., Oesterheld,M., Pagel,P., Ruepp,A., Mewes,H.W. and Stumpflen,V. (2006) MPact: the MIPS protein interaction resource on yeast. Nucleic Acids Res., 34, D436–D441. 5. Alfarano,C., Andrade,C.E., Anthony,K., Bahroos,N., Bajec,M., Bantoft,K., Betel,D., Bobechko,B., Boutilier,K., Burgess,E. et al. (2005) The Biomolecular Interaction Network Database and related tools 2005 update. Nucleic Acids Res., 33, D418–D424. 6. Hermjakob,H., Montecchi-Palazzi,L., Bader,G., Wojcik,J., Salwinski,L., Ceol,A., Moore,S., Orchard,S., Sarkans,U., von Mering,C. et al. (2004) The HUPO PSI’s molecular interaction format—a community standard for the representation of protein interaction data. Nat. Biotechnol., 22, 177–183. 7. Persico,M., Ceol,A., Gavrila,C., Hoffmann,R., Florio,A. and Cesareni,G. (2005) HomoMINT: an inferred human network based on orthology mapping of protein interactions discovered in model organisms. BMC Bioinformatics, 6, S21.