Australian researchers have developed lab-grown heart tissues that closely mimic adult heart muscle, a breakthrough for treating genetic heart diseases in children. Created from human stem cells, these “cardiac organoids” were matured using biological cues that simulate exercise. The study, led by QIMR Berghofer and partners in Melbourne, shows the organoids can replicate conditions like Desmoplakin cardiomyopathy. The diseased tissue responded to experimental BET inhibitors, offering hope for new therapies. Published in Nature Cardiovascular Research, the work could speed drug development and improve outcomes for young heart patients.