Basic local alignment search tool (BLAST) is a sequence similarity search program. The National Center for Biotechnology Information (NCBI) maintains a BLAST server with a home page at http://www.ncbi.nlm.nih.gov/BLAST/. We report here on recent enhancements to the results produced by the BLAST server at the NCBI. These include features to highlight mismatches between similar sequences, show where the query was masked for low-complexity sequence, and integrate information about the database sequences from the NCBI Entrez system into the BLAST display. Changes to how the database sequences are fetched have also improved the speed of the report generator.