A seven-year-old’s life was saved after German doctors grew genetically modified skin and transplanted it onto 80% of his body. It’s the first time this procedure has ever been done.

Hassan suffers from a rare genetic disease that results in blisters and open wounds all over his body. Doctors used a highly-experimental procedure to engineer skin cells, using the patient’s own stem cells. He spent eight months in intensive care. But now, nearly two years after the treatment, Hassan is living a normal life.