We therefore believe that there are, however limited, clear experimental reasons to believe that autologous MSCs could be of benefit in neurodegenerative disease. There are few, if any, reasons to fear that such cells are intrinsically likely to have adverse effects. Although the balance of evidence may arguably not be sufficient to overcome the hazards of intra-arterial or, more obviously, intracerebral implantation, intravenous delivery is very likely to be harmless, and indeed cardiological and extensive other clinical experience supports that likelihood. It is absolutely vital, of course, to continue the further investigation of MSCs and their basic and applied biological properties, but, in light of the above progress, we believe that, in progressive and untreatable neurodegenerative diseases such as MSA, a case can be made for cautious pilot clinical studies.

CONFLICT OF INTEREST
The authors declared no conflict of interest.