Scientists identify antivirus system

Viruses have led scientists at Washington University School of Medicine in St. Louis to the discovery of a security system in host cells. Viruses that cause disease in animals beat the security system millennia ago. But now that researchers are aware of it, they can explore the possibility of bringing the system back into play in the fight against diseases such as sudden acute respiratory syndrome (SARS), West Nile virus, dengue and yellow fever.