Heart Muscle Cells (IMAGE) Max-Planck-Gesellschaft Caption Stem cells play a part in heart regeneration. This image of the fluorescence microscope depicts a section of the heart tissue of a mouse. The green coloring of the cells in the middle shows that the cell originated from a so-called Sca1 stem cell. Credit MPI for Heart and Lung Research 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.