Swedish doctors report that a 10-year-old girl has had a major blood vessel in her body replaced with one grown with her own stem cells.
She had poor blood flow between her intestines and liver.
A vein was taken from a dead man, stripped of its own cells and then bathed in stem cells from the girl.
Surgeons said there was a "striking" improvement in her quality of life.
This is the latest is a series of body parts grown, or engineered, to match the tissue of the patient.