Dr. Gary Steinberg

Irreversibly.

So I think this is very important to highlight the dangers of stem cell therapy in general.

There's a lot of hope for it.

I mean, we're engaged.

We're just finishing a trial, a first in human trial at Stanford using cells we developed in my lab 20 years ago.

It took us 20 years to prove that they were safe, effective, didn't cause tumors.

And

the study is looking very promising.

It's a phase one study and we're making plans to do a phase two study with control patients, which you always want to do.

But despite the hope, there is still a lot of hype.

And I think it's very important to be careful about getting therapies that are not proven.

Some of the approaches to treat diseases of the brain or injuries to the brain are not injecting directly into the brain.

They're injecting intravenously or intra-arterial, threading a catheter up, as we discussed, and injecting in the brain.

Those cells, it turns out, don't even get into the brain.

And the idea is that in some of the better studies that have been done in animals, that they work by modulating the immune system systemically.

Those cells get trapped in the lung and the spleen, which people describe as bioreactors, and modulate the immune system, which does make some sense.

As I say, we think one of the main benefits of these stem cells

is that they modulate the immune system, and that helps with plasticity in the brain.

But even intravenous delivery can be dangerous to the brain.

Yeah, we don't want to oversell this, but some of the results in certain patients are remarkable.