Viruses are major pathogens in humans, and in the organisms with which we share this planet. The massive health and economic burden these agents impose has spurred a huge research effort to understand their most intimate details. One outcome of this effort has been the production, in many but certainly not all cases, of effective vaccines and therapies. - other consequence has been the realization that we can exploit viruses and put them to work on our behalf. Viruses are still seen to have the most - tential as vehicles for gene delivery and other therapeutic applications. However, their ability to exploit cellular functions to their own ends makes viruses not only highly effective pathogens but also exquisite experimental tools. Work with viruses underpins much of our current understanding of molecular cell biology and related fields. For membrane traffic in parti- lar, viruses have been crucial in providing insights into key cellular fu- tions and the molecular mechanisms underlying these events.

Viral Entry.- The Many Mechanisms of Viral Membrane Fusion Proteins.- The Role of the Cytoskeleton During Viral Infection.- Nuclear Import in Viral Infections.- Viral RNA Replication in Association with Cellular Membranes.- Synthesis and Quality Control of Viral Membrane Proteins.- Receptor Modulation in Viral replication: HIV, HSV, HHV-8 and HPV: Same Goal, Different Techniques to Interfere with MHC-I Antigen Presentation.- Trafficking of Viral Membrane Proteins.