Zanpar, without trying to be combative at all, I would like to point out that this is a 14 year old study. It's the one that is quoted in most other research to date, and is listed right at the top of the summary report you previously posted. So yes, it was interesting back then, but it's old info, not new.

What I would like to see now is more research on several different growth factors, not just GDNF, particularly those that are in peptide form and can cross the BBB without having to be surgically implanted. That would also allow for study designs that don't have to be open label. I would also like to see advances in biomarker and imaging research so we can test more definitively if these drugs/procedures are actually working.