Basal Keratinocytes (image) The Optical Society Caption This shows images of basal keratinocytes, the most common cells in the outermost layer of skin. The images were taken of the forearms of a 24-year-old (a), a 47-year-old (b), a 59-year-old (c) and a 69-year-old (d). Compared to the skin cells of the youngest volunteers, the skin cells in older subjects were larger, more irregular in shape, and showed spaces between cells, as indicated by the white arrows in images b-d. Credit Biomedical Optics Express Usage Restrictions None Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.