Does the 'Kissing disease' virus cause breast cancer?

Epstein-Barr virus, the cause of infectious mononucleosis, or 'mono', also called the 'kissing disease', is a known cause of head/neck, blood, and stomach cancer as well as others. New research has now shown that the virus can cause breast cells to become cancerous as well. Whether the virus causes breast cancer in humans is not yet known.

Because about 90% of people in the world have been infected with this virus at some time, the results make the development of a vaccine even more important.