Differences in these genes help explain why Epstein-Barr Virus (EBV) can have lasting health effects, in some people but not others. In a landmark study published in Nature, the team analyzed genetic and health data from approximately 750,000 people in the UK and US.

EBV infects nearly everyone—around 90% of people—but typically remains silent in the body. For some, however, this common virus can persist at higher levels and can contribute to serious chronic illnesses, including lupus, chronic lung disease, heart disease and certain cancers later in life—a mystery that has long challenged scientists.