Within this study we could demonstrate that NSDV/GV is able to block the innate immune system at three different stages, type I IFN induction, type I IFN action and type II IFN action. NSDV/ GV seems to be another example of a pathogen that exploits the host cell ubiquitin pathways for its own good by encoding an enzyme with deubiquitinating and deISG15ylating activity. However, to fully clarify the role of the OTU activity, an OTU knock-out virus is needed to evaluate the importance of the OTU domain in vivo, and we are working towards such a system. An advantage of NSDV/GV will be the ability to carry out such experiments in the natural host.