Surgeons transplanted a kidney and thymus gland from a gene-edited pig into a 54-year-old woman in an attempt to extend her life. It's the latest experimental use of animal organs in humans.

Surgeons at Massachusetts General Hospital said they transplanted a genetically edited pig kidney into a living human for the first time. The 62-year-old recipient has end-stage kidney disease.

Scientists are optimistic that gene-edited animals could provide a new source of organs for transplantation. Pig organs modified to minimize rejection are now being tested in humans.