Mice (IMAGE) Salk Institute Caption Mice that are unable to fully activate the powerful tumor suppressor p53 are resistant to high doses of radiation. The only noticeable effect is a premature graying of their coat. Both mice are the same age. Credit Image: Courtesy of the Salk Institute for Biological Studies Usage Restrictions News media reproduction to illustrate this story permitted with proper attribution as provided above. For one time use only. License Licensed 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.