The goal of our project is to develop methods to induce stem cells to differentiate into heart cells. Importantly, there are three major types of heart cells, which correspond to the ventricle (the major chambers that pump blood to the body), the atria (the smaller chambers that pump blood to the ventricles), and the nodes (these are the regions within the heart where the “pacemaker” cells are found, which control the heart rate). If we can produce pure populations of ventricular, atrial, or nodal cells, we can potentially use these cells for “replacement therapy” for patients which have had heart attacks or who have developed arrhythmias. During the first year of the research, we succeeded in producing cells that correspond to the ventricle. Furthermore, we have developed novel culturing techiques that improve the differentiation of the cells into atrial and nodal type myocytes, and the new strategies look very promising for the future research of this project.