 NR2F1A is a transcription factor that plays a key role in regulating the development of the heart. It is essential for maintaining the identity of cardiomyocytes, which are cells found in the heart muscle. When NR2F1A is absent or reduced, it can lead to the formation of abnormal heart structures and arrhythmia. This study shows how NR2F1A helps to maintain the identity of cardiomyocytes by preventing them from becoming pacemaker cells, which are responsible for controlling the heartbeat. By studying the effects of NR2F1A on cardiomyocytes, researchers were able to identify a specific region of DNA that is important for maintaining their identity. They also discovered that this region is responsible for regulating the expression of genes involved in the development of pacemaker cells. This article was authored by Kendall E. Martin, Padma Priyadasaniravazankar, Manabirans, and others.