We also plan to continue developing tools for the automatic identification of recoding events from nucleotide sequences. As the field grows and the number of recoded genes progressively increases, it becomes harder to extract data from the relevant literature and a number of novel recoded genes may escape the database. Therefore, we encourage users and researchers in the field to submit their data directly to the Recode-2 database. We are also willing to provide help with the analysis of potential new recoding events. ViralORFeome: an integrated database to generate a versatile collection of viral ORFs Large collections of protein-encoding open reading frames (ORFs) established in a versatile recombination-based cloning system have been instrumental to study protein functions in high-throughput assays. Such ‘ORFeome’ resources have been developed for several organisms but in virology, plasmid collections covering a significant fraction of the virosphere are still needed. In this perspective, we present ViralORFeome 1.0 (http://www.viralorfeome.com), an open-access database and management system that provides an integrated set of bioinformatic tools to clone viral ORFs in the Gateway® system. ViralORFeome provides a convenient interface to navigate through virus genome sequences, to design ORF-specific cloning primers, to validate the sequence of generated constructs and to browse established collections of virus ORFs. Most importantly, ViralORFeome has been designed to manage all possible variants or mutants of a given ORF so that the cloning procedure can be applied to any emerging virus strain. A subset of plasmid constructs generated with ViralORFeome platform has been tested with success for heterologous protein expression in different expression systems at proteome scale. ViralORFeome should provide our community with a framework to establish a large collection of virus ORF clones, an instrumental resource to determine functions, activities and binding partners of viral proteins. The number of viral genomic sequences available in public databases has increased exponentially, opening new perspectives to understand genetic basis and functional mechanisms that underlie virus replication, pathogenesis and evolution. In particular, this enabled to establish for each virus a list of potential regulatory and expressed sequences, a framework often referred as the 'parts list' of biological systems (1) . Current investigations aim at understanding how these viral components act upon each other and interact with host macromolecules to carry on viral replication and spreading. To reach such a system view of virus cycles, more functional analyses of viral components are necessary, especially in the field of virus-host molecular interactions (2, 3) . To address this question, a large collection of viral open reading frames (ORFs) established in a recombination-based cloning system allowing their mass transfer into various functional assays would be extremely helpful. Such ORF collections, often referred as 'ORFeomes', have been developed for human and few other organisms and represent great resources to explore protein functions in a large-scale setting (4) (5) (6) (7) (8) (9) . Recombination-based cloning technologies like the Gateway Õ system enable the mass cloning of polymerase chain reaction (PCR)-amplified ORFs into a 'donor' vector to create 'entry' clones. Once entry clones have been established, ORFs can be easily recombined into different 'destination' vectors that allow protein expression. So far, only few viral ORFeomes have been built and they are dedicated to a single virus, arguing that much more needs to be achieved (10) (11) (12) (13) .