Not yet investigated
What we have so far
The name was contested by the man who coined it: they are mostly not stem cells, and what they do appears to be signalling rather than replacing.
This star is on the map because the show intends to take the question apart properly — the trials, how it is actually tested, whether the thing sold is the thing studied. That work is not done yet, and nothing here should be read as a conclusion. When the investigation is published it will appear on this page.