To access protein-protein interactions from a list of proteins ( Figure 4B ), users have: (i) to select all or a subset of proteins of interest; (ii) to define the kind of interactions to retrieve (virus-virus, virus-host and hosthost) and their database origin and (iii) to select the mode of navigation to perform, either protein neighbours or protein subgraph ( Figure 4C ). Neighbours are viral or cellular proteins interacting directly with a protein of interest. A subgraph (or subnetwork) is a graph made of all interactions between a set of proteins. The resulting host-host, virus-host and/or virus-virus protein-protein interactions are then given into a tabulated format in three independent tabbed panels ( Figure 4D ). For each protein-protein interaction, users have a privileged access to interaction meta-data ( Figure 4E ) and a colour code highlights interactions that have been checked by VirHostNet experts.