Enlarge / This photomicrograph depicts leukemia cells that contain Epstein Barr virus using an FA staining technique, 1972. Epstein-Barr virus, EBV, is a member of the Herpesvirus family and is one of the most common human viruses. Evidence is mounting that the garden-variety virus that sometimes causes mono in teens is the underlying cause of multiple sclerosis, a rare neurological disease in whi