Scarring Effects (IMAGE) Walter and Eliza Hall Institute Caption Pictured are the cells that form clusters in the thymus with age. On the left, the thymus from a two-month-old mouse has few age-associated clusters (in blue). On the right, the thymus from a 24-month-old mouse shows many clusters. Researchers have found these clusters form ‘scars’ in the thymus which prevent the organ from restoring itself after damage. Credit: WEHI Credit WEHI Usage Restrictions Free to share, must credit License Original content 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.