Pretty cool - particularly given the chronic shortage of organ donors.

http://www.popsci.com/science/article/2011-07/using-lab-grown-trachea-surgeons-conduct-worlds-first-synthetic-organ-transplant

Surgeons working at Karolinska University Hospital in Sweden have taken a huge step forward for regenerative medicine by successfully executing the world’s first synthetic organ transplant. The donor-less transplant saved the life of a 36-year-old cancer patient, who is doing well now after having received a new windpipe grown from his own stem cells.