We age, in part, because the adult stem cells in our tissues are surrounded by chemicals that prevent them from replacing damaged cells. One of these chemicals is TGF-beta1, known to depress stem cell activity. A new study shows that a drug that blocks TGF-beta1, which is now being tested for its anticancer properties, makes brain and muscle tissue more youthful. This is a step toward a drug cocktail that could rejuvenate aging tissue.