In a breakthrough that could redefine organ transplantation, doctors in China have successfully implanted a genetically engineered pig liver into a 71-year-old man suffering from end-stage liver disease. The procedure marks the first time a pig liver has supported human life for more than a month, offering a new path forward for patients who have no access to donor organs.
The operation took place at Anhui Medical University’s First Affiliated Hospital in Hefei, led by Professor Beicheng Sun and his team of surgeons and geneticists. The patient had hepatitis B-related liver cirrhosis and liver cancer. Conventional transplantation was not an option because of his medical condition. In an experimental attempt to prolong life, the surgical team performed what is known as an auxiliary xenotransplantation, implanting the pig liver alongside the patient’s diseased liver rather than replacing it completely.
The donor organ came from a genetically modified Diannan miniature pig. Scientists altered ten genes in the pig to make its organ more compatible with human physiology, removing genes that provoke immune rejection and adding human genes that help the body accept the organ. This careful genetic engineering was key to the liver’s ability to function after transplantation.
According to The Sun’s report, the modified pig liver was also treated under strict biosecurity protocols to prevent cross-species infection risks, a crucial safety step in xenotransplant research.
This case proves that a genetically engineered pig liver can function in a human for an extended period. It is a pivotal step forward, demonstrating both the promise and remaining hurdles, particularly regarding coagulation dysregulation and immune complications, that must be overcome.Dr. Beicheng Sun, Professor and Surgeon, Nanjing University
The surgery, performed in China and later published in the Journal of Hepatology (October 2025), was successful in the initial stages. The pig liver started working immediately, producing bile, synthesizing proteins, and performing essential metabolic functions.
For more than a month, the transplanted organ functioned well. However, around day 38, the patient developed xenotransplantation-associated thrombotic microangiopathy (xTMA), a complication where small blood vessels in the graft become damaged due to immune reactions and clot formation. According to reports on The Sun, despite advanced medical treatment, including plasma exchange and drugs to control immune activity, the patient’s condition worsened, and he passed away 171 days after the initial surgery.
Medscape noted that even after the pig liver stopped functioning optimally, the patient’s condition stabilized temporarily due to partial liver support from his native liver, demonstrating that auxiliary xenotransplantation can buy valuable survival time.
Scientists caution that the liver is uniquely complex, performing extensive metabolic, immune, and coagulation-related roles. Therefore, short-term success, whether ten days or over a month, does not yet guarantee sustainable, long-term function.
The success of this procedure provides vital scientific evidence that pig organs can temporarily sustain human life. Across the world, thousands of patients die every year while waiting for liver transplants. According to the World Health Organization, less than 10 percent of people in need of an organ transplant actually receive one.
Researchers emphasized that the liver’s successful function for over a month demonstrates major progress in overcoming hyperacute immune rejection, an obstacle that had previously limited xenotransplants to a few hours or days in animal studies.
This experiment suggests that genetically modified pigs could eventually serve as a renewable source of donor organs, potentially reducing deaths from organ shortages. While researchers have previously transplanted pig hearts and kidneys into humans, the liver presents unique challenges due to its complex immune and metabolic functions.
Unlike the previous pig heart transplant cases in the U.S., which required full organ replacement, this auxiliary approach allowed doctors to observe both graft performance and host-liver interaction, an important advance in xenotransplantation science.
Experts see this case as a step forward in understanding how xenotransplantation, the use of animal organs in humans, might become a viable medical option in the future. The study highlights both progress and limitations: genetic modifications can reduce rejection, but immune and clotting complications remain major hurdles.
Following the success, the Anhui research team announced plans to conduct further clinical studies involving short-term auxiliary transplants in patients with acute liver failure to assess safety, viral transmission risk, and immune control protocols.
Scientists are now focusing on improving genetic engineering techniques, refining immunosuppressive therapies, and establishing ethical and safety frameworks for human use. Although this transplant did not result in long-term survival, it has demonstrated that a pig liver can function in a human body long enough to make a medical difference.
The researchers also collaborated with eGenesis, a biotechnology firm specializing in genome-edited pigs, highlighting a growing global partnership in advancing cross-species transplantation research.
The achievement stands as an important milestone, one that may one day lead to reliable, life-saving alternatives for patients waiting for organ transplants worldwide. As scientists refine these methods, questions about safety, consent, and cross-species ethics will remain central to the future of xenotransplantation.
References:
1. Zhu, Jianwei et al. “First Pig-Liver Xenotransplantation into a Living Human: A Phase I/II Study.” Journal of Hepatology, forthcoming. https://doi.org/10.1016/S0168-8278(25)02497-3.
2. “Pig Liver Organ Transplant Living Human Patient – First Study.” The Sun, 27 October 2025. https://www.thesun.co.uk/health/36947681/pig-liver-organ-transplant-living-human-patient-first-study/
3. Medscape. “First Pig Liver Transplant in Living Recipient Shows Promise.” (October 2025). https://www.medscape.com/viewarticle/first-pig-liver-transplant-living-recipient-shows-promise-2025a1000rr6
(Rh/SS/MSM)