Researchers at Uppsala University in Sweden reported in August that a simple blood test may be able to predict who is most likely to die of heart disease or cancer. In a 12-year study of nearly 2,000 people, the researchers found that those with higher levels of an enzyme called cathepsin S were more likely to die than those with lower levels. The enzyme, which helps break up certain proteins, tends to be higher in people with heart troubles or tumors, and may contribute to atherosclerosis, so people with higher levels of the enzyme are more likely to die of these diseases, the researchers found. Cathepsin S is also abundant in fat tissue, which isn't surprising since being overweight is a major risk factor for heart events.
It's not clear yet exactly how cathepsin S contributes to either heart disease or cancer, but drug companies are already busy working on compounds that might block its effects.