PHI-BLAST is a BLAST server that uses protein sequences from the Pathogen-Host Interaction database (PHI-base, www.phi-base.org) as the database from which to perform BLAST searches using a user-supplied sequence.
The PHI-BLAST tool is available from http://phi-blast.phi-base.org/.
The source code for PHI-BLAST was originally cloned from SequenceServer, which in turn is based on the BLAST+ software.