The first man transplanted with a genetically modified pig kidney was discharged in Boston, USA, this Wednesday, two weeks after the intervention, The New York Times reported. Richard Slayman, 62, was operated on by surgeons at Massachusetts General Hospital on March 16 in an operation that lasted four hours, and after being discharged, he will continue his recovery at home.

According to his doctors’ report, the kidney Slayman received “produces urine, removes waste products from the blood, balances body fluids, and performs other key functions.”

The result is an important milestone for medicine and makes it easier for patients to find organs, the medical center said in a statement after the operation. Experiments with organ transplants from modified pigs had failed until before Slayman’s intervention. Two patients received hearts, but died shortly afterward.

“This moment – leaving the hospital today with one of the cleanest clean bill of health I have had in a long time – is one I have hoped would come for many years. Now it is a reality and one of the happiest of my life,” Slayman said in a statement.

In the writing, the man also thanked his doctors and the people who have accompanied him and have been interested in his story. “Especially to patients waiting for a kidney transplant. Today marks a new beginning not only for me, but also for them,” he said.

It is still uncertain whether Slayman’s body will eventually reject the transplanted organ, and experts say that for xenotransplants (transplants between different species) to become widely available, more similar operations and clinical studies need to be carried out.