jeffreyn wrote: "Hopefully it won't be too long before we see an MSCs-for-PD clinical trial that uses umbilical cord MSCs".

Not too long at all it seems! There are now TWO such trials.

The first one is in Jordan:
Use of Mesenchymal Stem Cells in Parkinson Disease (PD) - Full Text View - ClinicalTrials.gov

The second one is in China:
Umbilical Cord Derived Mesenchymal Stem Cells Therapy in Parkinson's Disease - Full Text View - ClinicalTrials.gov

Aside:
I was thinking about "plasma fractions" (such as GRF6021 from Grifols/Alkahest), and it reminded me of this thread from last year about (umbilical-cord-derived) mesenchymal stem cells (MSCs).

As I wrote earlier in the thread: "My understanding of MSCs is that they are found throughout the body, they modulate the immune system, decrease inflammation, and stimulate regeneration. They do not [necessarily] transform into other types of cell. Their influence [potentially] occurs via the production of cytokines and growth factors."

Simplistically, it seems to me that with plasma fractions you assemble a collection of molecules (proteins) and then inject them, whereas with MSCs it's the MSCs that create the molecules (after they themselves have been injected)!