The PhEVER web interface allows for two query forms represented in Figure 4A and B. On the one hand ( Figure 4A ), the HoSeqI tool allows to search in PhEVER families with a user provided query (15) . This query is used to BLAST the proteins present in PhEVER and to match the most related family. Alignments and phylogenies for this new family containing the user provided sequence can be recomputed on the fly, visualized and manipulated with Java applets ( Figure 4F ) (31, 32) . On the other hand ( Figure 4B ), the query tool allows to directly query the database with a very diverse range of terms including gene name, annotation term, species name, protein accession number, genome accession number and family accession number. The species and sequences represented in each family detected by the query can then be viewed ( Figure 4D ) as well as the alignments and phylogenies which can be edited online via Java applets ( Figure 4E ) (31, 32) . More details on how to query PhEVER are presented in the Supplementary Data.