Doctors in Boston announced Thursday they have transplanted a pig kidney into a 62-year-old patient.

Massachusetts General Hospital said it’s the first time a genetically modified pig kidney has been transplanted into a living person. Previously, pig kidneys have been temporarily transplanted into brain-dead donors. Also, two men received heart transplants from pigs, although both died within months.

The experimental transplant was done at the Boston hospital on Saturday. The patient, Richard “Rick” Slayman of Weymouth, Massachusetts, is recovering well and is expected to be discharged soon, doctors said Thursday.

Slayman had a kidney transplant at the hospital in 2018, but had to go back on dialysis last year when it showed signs of failure. When dialysis complications arose, his doctors suggested a pig kidney transplant, he said in a statement released by the hospital.