The world's fifth living-body alien organ transplant, the first liver transplant from a pig to a living human, was successfully completed by the First Affiliated Hospital of Anhui Medical University on May 17. It brings new hope to the over 140,000 domestic registered patients waiting for an organ transplant and the possibly higher number of unregistered people facing organ failure.

Although a living person can donate part of his or her liver without sacrificing his or her life, the operation in Anhui province is still a significant development because compatible liver sources are not that easy to find and a liver transplant involves high medical costs and pain to get part of the liver from a donor. A liver transplant is even more complicated than that of a heart and kidney that function as blood pump and water cycler respectively, as the liver is involved in metabolism, immunity, digestion and many more functions.

The Anhui hospital's transplant operation is medically considered a success because the transplanted pig liver is reportedly operating normally in the patient's body, secreting 200 millilitres of gall every day.

A fact that cannot be omitted is that in previous cases the patients in the United Kingdom and the United States who received heart and kidney transplants from pigs all passed away within two months after receiving the organs. The transplant operations have still prolonged the patients' lives and sustained them without a rejection reaction after the transplant operations till their deaths. Further, the transplanted liver in the domestic case had only 10 genes edited to prevent a rejection reaction, fewer than the transplanted hearts and kidneys in the US and UK cases, which shows that domestic medical experts may have developed a methodology that can support the patient's survival without changing the liver too much.

With the gene-editing technology aimed at "cutting" more gene clips that trigger a rejection reaction away from pig organs maturing, the risks of transplanted alien organs being rejected will be minimized and the technology will be applied more widely to save lives.