A paralysed man has been able to walk again after a pioneering therapy that involved transplanting cells from his nasal cavity into his spinal cord.
Darek Fidyka, who was paralysed from the chest down in a knife attack in 2010, can now walk using a frame, the BBC reports.
The treatment, a world first, was carried out by surgeons in Poland in collaboration with scientists in London.
Details of the research are published in the journal Cell Transplantation.
BBC One's Panorama programme had unique access to the project and spent a year charting the patient's rehabilitation.
Darek Fidyka, 40, was paralysed after being stabbed repeatedly in the back in the 2010 attack.
He said walking again - using a frame for support - was "an incredible feeling".
"When you can't feel almost half your body, you are helpless, but when it starts coming back, it's like you were born again."
Prof Geoff Raisman, chair of neural regeneration at the Institute of Neurology, UCL, led the British research team.
He said what had been achieved was "more impressive than man walking on the Moon".