Scientists at the Hubrecht Institute in the Netherlands have discovered that a protein found in zebrafish, known as Hmga1, can repair damaged mouse hearts. The protein stimulates heart muscle cells to divide and grow, significantly improving heart function. The researchers believe that this breakthrough could lead to potential treatments to prevent heart failure in humans. The gene for Hmga1 is present in humans and active during embryonic development, providing a foundation for gene therapies that could unlock the heart's regenerative potential in humans. However, further refinement and testing of the therapy is needed before it can be brought to the clinic.