Reporting in Nature Communications on Feb. 9, they describe how cellular survival after radiation exposure depends on behavior of p53 over time. In vulnerable tissues, p53 levels go up and remain high, leading to cell death. In tissues that tend to survive radiation damage, p53 levels oscillate up and down. “Dynamics matter. How things change over time matters,” said co-corresponding author Galit Lahav, the Novartis Professor of Systems Biology at HMS. “Our ability to understand biology is limited when we only look at snapshots. By seeing how things evolve temporally, we gain much richer information that can be critical for dissecting diseases and creating new therapies.”