What have RNAi screens taught us about viral-host interactions?

The blossoming of genomic technologies and miniaturization has opened up the field of genomic scale cell-based screening to the study of viral-host interactions. RNAi technology, while still at its infancy, is being used to identify cellular factors required for various viral infections. This has led to the discovery of hundreds of new factors, and has increased our knowledge of the host factors that impact viral infection and highlighted the cellular pathways at play.