Chromatin Opening (IMAGE) University of Pennsylvania School of Medicine Caption TCF-1 opens chromatin so that DNA can be read to make proteins, and keeps chromatin open so that subsequent factors can access DNA to make protein that guide a maturing T cell to its final identity. Credit The lab of Golnaz Vahedi, PhD, Perelman School of Medicine at the University of Pennsylvania 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.