BBC News reported more than a quarter of a middle-aged person’s skin may have already made the first steps towards cancer, a study suggests.
Analysis of samples from 55- to 73-year-olds found more than 100 DNA mutations linked to cancer in every 1 sq cm (0.1 sq in) of skin.
The team, at the Sanger Institute, near Cambridge, said the results were “surprising”.
Experts said prevention was the best defence against damage from the sun.
Skin cancer is one of the most common cancers.
Ultraviolet-radiation from sunlight bombards our skin and transforms it from healthy to cancerous tissue.