A protein called Med25, found in human breast cancer cells, was notoriously undruggable. As a transcriptional coactivator, the protein influences gene activation by using its flexible structure to bind to DNA and other proteins inside a cell. But it’s this unstable structure that stumped researchers challenged with developing a small molecule to inhibit the protein’s activity.

Now, a team of scientists in Dr. Anna Mapp’s lab at the University of Michigan have discovered a chemical compound that does just that, and they found it in nature of all places. The compound is produced in lichens and binds to a secondary site on Med25, leading researchers to believe it could also be effective at targeting other previously undruggable proteins that are potential targets for novel therapeutics.