No one wants to contract herpes, but it may even be more of a concern for women, according to new research that found it could put some women at increased risk for getting breast cancer.

The study, published in the July issue EBioMedicine, found that the Epstein-Barr virus (EBV), the most common of the eight known viruses in the herpes family, could contribute to a woman getting developing breast cancer.

EBV is best known as the cause of infectious mononucleosis, otherwise known as mono. More than 90 percent of people globally carry EBV, though most never experience symptoms. It has been linked to illnesses such cancer and Hodgkin’s disease, but it is still difficult to identify what diseases it triggers.

A team of scientists led by Gerburg Wulf, MD, PhD, a physician in the hematology/oncology division at Beth Israel Deaconess Medical Center and an associate professor of medicine at Harvard Medical School, studied primary mammary epithelial cells found in the breast and examined their reactions in the presence of EBV.

Testing their theory on mice, they implanted primary mammary epithelial cells and the EBV and found that the virus cooperated with certain cancer-causing proteins that accelerated the formation of breast cancer. The infected mammary cells had genetic characteristics associated with an aggressive breast cancer receptor.

The virus binds to the CD21 receptor in normal breast cells, which eventually leads to infection. The infection causes the cells to take on characteristic of stem cells, which allows them to continue dividing.

EBV has also been linked to breast cancer in other studies around the world in India, China, Africa and southern Europe.

Though Wulf’s study cannot necessarily prove EBV causes breast cancer, the research does indicate that it contributes to the development of it, making the case for the creation of an EBV vaccine.