When trying to beat back a patient’s cancer, doctors struggle to sic chemical treatments on cancer cells while mostly leaving healthy cells alone and safe. This critical feat would be much easier if doctors could spot a common difference between invasive cancerous cells and healthy ones.

Now, researchers suggest they’ve found such a tell for certain metastatic cancers: a fatty acid receptor protein called CD36. In a new study published in Nature, researchers show that interfering with that protein almost completely inhibits the development and spread of cancer in mouse models of human oral cancer—and causes zero side-effects. Though the study was only done in mice, researchers are hopeful that the technique could be a promising new strategy to treat cancer in human patients in the future.

The study, led by researchers at the Barcelona Institute of Science and Technology (BIST), involved cultured cells from human oral carcinomas. These human cancer cells were injected into the mouths of healthy mice. As expected, the mice developed oral cancer. Among the types of cancer cells contributing to the rodent’s tumors was a particular type of cell referred to as CD44bright cells, which are known culprits behind oral cancers in humans.