Paralysed man walks again after cell transplant
21 October 2014 Last updated at 23:27 BST
This report contains scenes of surgery.
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 paralyzed from the chest down in a knife attack in 2010, can now walk using a frame.
The treatment, a world first, was carried out by surgeons in Poland in collaboration with scientists in London.
Fergus Walsh reports.