Japan has become the first country to approve a stem-cell treatment for Parkinson’s disease, and it could be available to patients as early as this summer. The therapy, Amchepry, is made by Sumitomo Pharma and involves transplanting reprogrammed iPS cells into both sides of the brain to help improve motor symptoms like shaking and difficulty moving. During a small trial, millions of cells were implanted in the brains of participants. After two years, no major side effects were reported and four patients showed symptom improvements.