The overarching theme of research in the Bieniasz-Hatziioannou laboratory is to describe the role that host proteins play in enabling and inhibiting the replication of viruses. Virus reproduction in a particular host species or cell type requires that viruses parasitize host cell machinery required for replication, while evading or antagonizing host proteins that might otherwise prevent virus replication. Interactions between viruses and host proteins are thus fundamental drivers of virus and host evolution, and understanding the molecular details of how viral and host proteins interact and function during viral reproduction can lead to the discovery of interventions that ameliorate the burden of viral diseases.