Twelve Parkinson's patients received transplants of dopamine-producing cells derived from human embryonic stem cells, with the higher dose group (6.3 million cells) showing superior motor function recovery at one year compared to the lower dose (3.15 million cells). PET imaging confirmed graft survival through increased dopamine transporter activity in brain regions targeted for transplantation. This represents a significant advance in regenerative medicine for neurodegenerative disease. Cell replacement therapy for Parkinson's has been pursued for decades, but previous attempts using fetal tissue faced ethical concerns and inconsistent outcomes. The ability to generate standardized, high-purity dopamine progenitors from embryonic stem cells could overcome these limitations while providing scalable treatment. However, the small cohort size and open-label design limit definitive conclusions about efficacy. The 12-month follow-up period is also relatively short for assessing long-term graft integration and potential complications like dyskinesias that emerged in earlier fetal cell trials. The safety profile appears encouraging, but larger randomized controlled trials with extended follow-up will be essential to establish whether this approach can meaningfully alter disease progression rather than just temporarily masking symptoms.