Rhys Harris is writing a very important thank you note. Two years ago, the eight-year-old's life was saved by a bone marrow transplant after he had been confined to a "bubble" by a debilitating genetic disorder.
Rhys, from Newbridge in Caerphilly county, was diagnosed with a genetic disease called Nemo at the age of three. He lived in isolation in a sterile bubble - parents Kevin and Dawn were unable to hug or kiss him.
Now, a year after returning home from hospital in Liverpool, Rhys and his family are writing a thank you letter to the donor who saved his life.
The Harris's only know the donor is a man in his 40s but are sending the letter along with a parcel to the bone marrow unit in the USA in the hope that they can make contact.
Matt Murray reports.