The Dynamic Heart (image) University of Illinois at Urbana-Champaign Share Print E-Mail Caption The heart enlarges in response to growing demands from exercise or heart disease. A new study identifies a key molecular player in this process. Credit Graphic by Julie McMahon Usage Restrictions Credit: Graphic by Julie McMahon Share Print E-Mail 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.