A breakthrough treatment for multiple sclerosis (MS) has helped severely disabled patients walk, work and even ski again.
Experts say the results are very exciting, but the treatment is also very aggressive and potentially deadly.
It's hard to believe that Jennifer Molsen once couldn't walk. She was diagnosed with MS at the age of 21, yet now she's well enough to go skiing.
Ms Molsen took part in a ground-breaking clinical trial at the University of Ottawa. She says the experimental treatment gave her a second chance at life.
In MS, the central nervous system is damaged by the body's immune system.
During the trial, doctors harvested stem cells from 24 patients and froze them. Patients were then given high doses of chemotherapy drugs to destroy their immune system, and afterwards their preserved stem cells were returned to reboot their system.
Doctors say 70 percent of the subjects showed a halt in the progression of the disease, and some even saw symptoms reversed.
But the treatment is high-risk. One patient died from liver failure as others suffered side effects. Medical experts say wider studies are now needed.
There's still a long way to go, but the fact that severely affected patients like Ms Molsen can now lead a normal life is being seen as a beacon of hope.