Fibroblasts (IMAGE) Princeton University Caption Fibroblast cells are integral to the body's immune response and for healing wounds. A new Princeton University study reveals that when fibroblasts go to sleep, entering a phase researchers term "quiescence," they are more active than previously thought. Here they are shown, via an image produced by an inverted fluorescence microscope, streaming toward a wounded skin cell. Credit Image courtesy of Erin Haley Usage Restrictions None 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.