We study Epstein-Barr virus (EBV), the first human cancer-causing virus to be discovered. EBV causes infectious mononucleosis and is causal or linked to several B lymphocyte- and epithelial cell-cancers. Some of our experiments are designed to explore how EBV disturbs and exploits cellular physiology to drive unscheduled cell proliferation, a central feature of cancer. Other experiments are directed at understanding how this virus persists successfully in over 95% of humans. Both lines of investigation have revealed several targets for anti-cancer and anti-viral intervention.