 Olsen and colleagues have found that the heart plays a key role in controlling the metabolism of other organs such as the liver and white fat. They discovered that the heart releases certain molecules called cardiokines into the bloodstream, which then travel to these other organs and affect how they use energy. This process helps maintain proper energy balance throughout the body, leading to better health outcomes. This article was authored by Mithinari Nakamura and Junichi Sadashima.