When they carried out a post-mortem on the patient who died, they found some of the brain tissue that had been dying off through Alzheimer's had started to rejuvenate.
If the spinal cord is damaged in a way that cuts the bladder off from the brain, the nervous tissue below the break will often remodel itself to create a new bladder-emptying reflex.
When such a cell divides, at least one of its daughters is also a stem cell (the other may set off on the route to specialisation that allows stem cells to generate new tissue).
After the Botox wore off, one group had a face-lifting surgery combined with the removal of muscle tissue or nerves in the area that triggered the migraines.