Scientists are developing a simple blood test to measure how fast the body's tissues are ageing at a molecular level.
They have found that as tissue ages, concentrations of a protein called p16INK4a dramatically increases. Measuring levels of the protein could potentially provide a way to assess how healthy the tissues are, and how they will respond to surgery or drugs.
Scientists are already interested in p16INK4a because it is known to play a role in suppressing the development of cancer. The protein is present in the T-cells of the immune system, which play a key role in fighting disease, and repairing tissue damage.