Scientists who study viruses have long tried to harness their power to cause illness in healthy cells, and engineer them to attack and destroy cancer cells.

Now researchers at Washington University say they have shown that the Zika virus can kill stem cells in brain tumors in the lab.

Zika is a mosquito-borne virus that can cause severe brain damage in a developing fetus if the woman catches the virus when pregnant.

Since Zika affects stem cells in the fetus’ brain, scientists theorized that it might be able to infect stem cells in brain tumors.

“We take a virus, learn how it works and then we leverage it,” said Dr. Michael Diamond, a professor of molecular microbiology, pathology and immunology. “Let’s take advantage of what it’s good at, use it to eradicate cells we don’t want. Take viruses that would normally do some damage and make them do some good.”

Researcher Zhe Zhu thought that glioblastoma stem cells, which stubbornly resist chemotherapy and radiation to regrow in most patients, looked a lot like the stem cells in a fast growing fetal brain. Since the Zika virus kills those fetal cells, maybe it would do the same to the tumor cells.