A deadly larval pest may well help stave off cancer in humans. Researchers in the UK have found evidence that a parasitic caterpillar fungus contains a key ingredient that can be used to disrupt the growth of tumor cells.

The fungus is called Cordyceps militarismand it is the colorful relative of more infamous mushrooms known to mind control their victims. C. militaris itself is regularly used in traditional Chinese medicine, and some research has shown that a particular compound the mushroom produces—cordycepin—has anti-inflammatory and other properties that may make it valuable in treatment of cancer. Researchers at the University of Nottingham’s School of Pharmacy say they have now gained insight into how cordycepin can be used to attack cancer’s weak points.

The researchers first analyzed how cordycepin changed the activity of thousands of genes in different cell lines. Based on this analysis, they determined that the compound mainly works by blocking pathways that control cell growth. They also found the specific metabolic byproduct likely responsible for this effect, cordycepin triphosphate. This byproduct is similar to the molecule adenosine triphosphate (ATP), the “fuel” that cells use to carry out their functions.

The findings, is published Thursday in FEBS Letters, suggests that cordycepin or synthetic cousins ​​derived from it could be used to suppress cancer cell growth, the researchers said. The techniques they developed to study cordycepin’s activity in cells could help them and researchers to

“We have been researching the effects of cordycepin on a range of diseases for a number of years and with each step we get closer to understanding how it can be used as an effective treatment,” says study researcher Cornelia de Moor in a statement from the university. “Our data confirm that cordycepin is a good starting point for new cancer drugs and explain its beneficial effects.”

There are still more mysteries to be solved about cordycepin, the researchers say, such as the actual molecules in a cell that it interacts with to affect growth. But the techniques they developed to study cordycepin in cells could help them and other researchers in the future, because they could identify particular genes that were reliably activated by the compound. According to de Moor, this knowledge should make it easier to measure the effect that cordycepin has on, for example, a patient’s blood cells.

Derivatives of cordycepin are also already being tested in human trials as cancer treatment, with some early promising results. So it may not take long for the terrible appearance C. militarism to become a blessing to mankind.