Researchers from the Bakkers group at the Hubrecht Institute have successfully repaired damaged mouse hearts using a protein from zebrafish. They discovered that the protein Hmga1 plays a key role in heart regeneration in zebrafish. In mice, this protein was able to restore the heart by activating dormant repair genes without causing side effects, such as heart enlargement. This study, supported by the Dutch Heart Foundation and Hartekind Foundation, marks an important step toward regenerative therapies to prevent heart failure. The findings were published in Nature Cardiovascular Research on January 2, 2025.