ViralORFeome 1.0 is based on conventional sequence and virus databases. Virus and host organism classification was retrieved from the taxonomy database at National Center for Biotechnology Information [NCBI; ftp://ftp .ncbi.nih.gov/pub/taxonomy/; (16) ]. Complete viral CDS and associated annotations were downloaded from the CoreNucleotide division of GenBank [http://www.ncbi .nlm.nih.gov/sites/entrez?db=nucleotide; (17) ] using Entrez Programming Utilities (eUtils) at NCBI (see Supplementary Data). ICTV names were obtained from the most recent publication of the International Committee on Taxonomy of Viruses using Perl scripts (18) . Finally, host gene and protein sequence annotations were extracted from Ensembl database (19) .