Right now, arthritis treatment tends to be an all-or-nothing proposition: the drugs you take affect your entire body, causing havoc with your immune system and leaving you prone to infections. But how do you narrow the treatment to just those areas where you feel pain? Genetics, apparently. Researchers have used CRISPR gene editing to turn stem cells into cartilage that releases a biological anti-inflammatory drug when they encounter inflammation. It not only limits treatment to the affected area, but responds only when there's a pain flare. You only get relief when you need it.