Would you want to be young forever? An incredible scientific breakthrough might stop us getting old, ill and grey. Yet some think eternal youth is not all it is cracked up to be.
Eureka! Anti-ageing holy grail found
Arrested development: Left: Mouse that has the ageing gene knocked out. Right: Normally ageing mouse at 90-95 weeks old. Glossary
Gene - A gene is the basic unit of heredity.
Protein - Large biomolecules made of up amino acids, which in turn are made up of DNA.
Metabolism - The chemical processes within the body which produce energy. It derives from a Greek word meaning "change".