More than a quarter of the cells in aged, sun-exposed skin may carry cancer-causing mutations while maintaining their normal physiological function (Martincorena I et al. Science. 2015;348:880-886).
When a team led by investigators at the Wellcome Trust Sanger Institute, in the United Kingdom, sequenced the genomes of cells taken from 234 small biopsies removed from the eyelids of 4 adults aged 55 to 73 years, they observed 2 to 6 mutations per megabase per cell, which is similar to that seen in many cancers.
Hampton T. Striking Similarities Between Cancerous and Normal Skin Cells. JAMA. 2015;314(1):16. doi:10.1001/jama.2015.7178