https://www.nature.com/articles/s41586-020-2388-4
It was titled: Reversing a model of Parkinson’s disease with in situ converted nigral neurons
There were some controversies and in 2023 another publication told: Ptbp1 deletion does not induce astrocyte-to-neuron conversion
1) Developing cures for human diseases / health conditions. And 2) Understanding the mechanisms behind those diseases.
Obviously findings in mice don't apply to humans 1:1. Humans != mice. But that doesn't negate 2). Every single link in a complex process that's better understood, brings solutions closer to becoming reality. So 2) helps with 1) as well. Just in a less direct manner.
> Scientists cure sickle cell disease in mice.
> Scientists fully solve aging in mice by using modified rice starch.