It’s one of those stories that simultaneously gives great hope but also a little dread. Researchers in Pennsylvania say they’ve successfully stimulated the production of a pain-blocking protein in mice by using a modified herpes virus to attach the appropriate genes onto the animals’ DNA. That’s potentially terrific news. If the same technique held true in humans, it could offer a new way to treat the devastating pain associated with some forms of cancer, such as bone cancer. Of course, a hell of a lot of mice were bred specifically develop the extremely painful bone tumors, just so the technique could be tested. It’s no doubt a necessary sacrifice, but one that shouldn’t be overlooked entirely. You don’t have to be a wacko member of PETA to spare a thought for the millions of mice and other lab animals that are sacrificed each year so humans can live healthier lives.