A gene-silencing technique based on CRISPR can relieve pain in mice, according to a study1. Although the therapy is still a long way from being used in humans, scientists say it is a promising approach for squelching chronic pain that lasts for months or years. Chronic pain is typically treated with opioids such as morphine, which can lead to addiction.“It’sa real challenge that the best drugs we have to treat pain give us another disease,” says Margarita Calvo, a pain physician at the Pontifical Catholic University of Chile in Santiago, who wasn’t involved in the research. That’s why the new technique is exciting, she says.

Scientists are already evaluating CRISPR therapies that edit a person’s genome as treatments for blood diseases and some forms of hereditary blindness. The new version of CRISPR doesn’t edit genes directly—it stops them from being expressed—and so shouldn’t cause permanent changes, although it’s unclear how long its effects last for. Some studies estimate that a large proportion of the population in Europe and the United States—as high as 50%—experiences chronic pain2, 3. This pain can become debilitating over