copy of the sequence. In addition to the two examples above on region-based annotations, many other annotation databases from UCSC Genome Browser can be also interrogated. Additionally, ANNOVAR implemented the ability to directly interrogate any annotation databases conforming to Generic Feature Format version 3 (GFF3). Several examples of GFF3-based annotation databases are provided in the ANNOVAR website. GFF3 has become the standard annotation format among many established and emerging model organism databases, and provides a convenient standard for exchange of sequence feature annotation. Work with GFF3 files is widely supported by BioPerl and GMOD tools, thus it is relatively simple to convert most sequence feature annotations to GFF3 format. ANNOVAR leverages this standardization, so that users can utilize many custom built annotation databases for annotating genetic variants.
