The news comes from a mouse study done by researchers at UC San Francisco. If it pans out in people, it could answer a huge unmet need for therapies that treat these injuries, which are the leading cause of death in people under 44 years old. A research paper on this topic is published in the Blood Journal.

In addition to the immediate bleeding, traumatic brain injury (TBI) also causes dangerous brain swelling days later, as blood vessels begin to leak. Even if a person is rushed to the hospital, doctors have few options, aside from surgery, to stop the bleeding or the brain swelling.