NCBI Virus is an integrative, value-added resource designed to support retrieval, display and analysis of a curated collection of virus sequences and large sequence datasets. We are a community portal for viral sequence data, and our goal is to increase the usability of data archived in GenBank and other NCBI repositories. NCBI Viral Genomes Resource is a collection of virus genomic sequences that provides curated sequence data, related information and tools. It includes all complete viral genome sequences deposited in the International Nucleotide Sequence Database Collaboration (INSDC) databases, i.e. DDBJ, EMBL, and GenBank. Data are organized by viral taxonomy, and reference sequence records (RefSeqs) from one or more genome sequences for each viral species. After a RefSeq has been created for a species, other complete genomes from that same species are indexed as neighbors to the RefSeq.