Doctors in Boston say they have transplanted a pig kidney into a 62-year-old patient. Massachusetts General Hospital said Thursday 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 hospital announced the transplant Thursday and said the Massachusetts man is recovering well. Doctors say they expect the kidney to work for at least two years, and the patient could go back on dialysis if it fails.