Nature reports that scientists have brought osteoarthritis, an all too common age-related condition, to a halt in mice: "The researchers investigated a family of enzymes, called aggrecanases, that are thought to contribute to osteoarthritis by chewing up a vital component of cartilage that makes it tough and elastic. The teams showed that mice genetically engineered to lack a working form of one such enzyme, ADAMTS5, seem impervious to arthritis. ... Various enzymes come and go and all turn out to be dead ends. But now we might be on to something. ... The researchers are particularly hopeful because the mice lacking the working enzyme showed no signs of problems elsewhere in their bodies."