Researchers say they finally understand the connection between the autoimmune disease and Epstein-Barr virus.

One of the most common viruses in the world could be the cause of lupus, an autoimmune disease with wide-ranging symptoms, according to a study published Wednesday.

Until now, lupus was somewhat mysterious: No single root cause of the disease had been found, and there is no designated treatment for it.

The research, published in the journal Science Translational Medicine, suggests that Epstein-Barr virus — which 95% of people acquire at some point in life — could cause lupus by driving the body to attack its own healthy cells.