Multiple sclerosis (MS) causes damage to myelin, leading to neurological problems. Current treatments cannot repair this damage. Traditional animal models and cell cultures fail to replicate the complex function of the human brain. A new model, based on three-dimensional human brain tissue, provides a more accurate way to study remyelination. By simulating damage and introducing repair cells, scientists can test potential therapies. This approach has the potential to deliver new insights and accelerate the development of effective treatments for MS.