One man lived with a gene-edited pig kidney for 271 days, setting a record, before he received a human kidney.

Read why one man agreed to get a pig kidney in 2025 to replace his own failing organ

The 68-year-old New Hampshire man told USA Today that a motivator for the experimental surgery was his belief that he was going to die anyway, and other people suffering from kidney disease could gain valuable insights. Yet the surgery bought him time—he lived 271 days with a pig organ and later received a human kidney transplant. Clinical trials began in 2026 to test the pig xenotransplants in more people.

Scientists may have discovered why gene-edited pig kidneys are rejected in humans

In November 2025, researchers studying how a brain-dead donor’s body responded to the transplantation of a genetically engineered pig kidney, published that they’ve identified immune system reactions that may explain why these pig organs get rejected. What’s more, they were able to reverse the rejections with an already available drug combination and the kidney functioned well. They also pinpointed a way to detect a potential rejection up to five days sooner.

Chinese scientists transplanted a pig lung into a human being in 2025—but it had to be removed.

Xenotransplants are an experimental last resort for the terminally ill when they cannot or will not receive a human organ.

A first-of-its-kind clinical trial taps livers from gene-edited pigs to clean blood

The experimental dialysis-like treatment from United Therapeutics, eGenesis, and OrganOx, is designed to help people with liver failure. The therapy, which involves attaching the modified pig liver externally, filters a patient’s blood so their own livers can temporarily rest and perhaps heal.

The first successful organ transplant was performed in 1954

The successful kidney transplant procedure, at what's now-called Brigham and and Women's Hospital, ushered in a new medical era and gave hope to patients with organ failure. The recipient, 23-year-old Richard Herrick, lived eight more years after receiving the donated organ from his living twin brother, Ronald.

After the first gene-edited pig heart transplant patient died, a latent pig virus was discovered inside his xenotransplant.

White patients waited 374 days for a kidney—Black patients waited 727 days

A 2022 congressionally mandated report highlighted racial inequities in the US organ transplant system, including disparities that made it more likely white people will be placed on organ wait lists than Black people. It spotlighted inequities such as racial differences in median kidney wait times identified in earlier research. The report, from the National Academies of Sciences, Engineering, and Medicine, recommended fixes including that the Department of Health and Human Services develop national performance goals for the system and achieve equity in the system in the next five years.

In 2024, the US had more organ transplants than ever before—besting the 2023 record

More than 48,000 organ transplants were performed in 2024, and about 46,630 were performed in 2023. These record highs are illustrated here as part of data from 1988 to partway through 2025. Kidneys, livers, and the heart remain the most common transplanted organs. (Some users may encounter a paywall.)

See how pig heart valves have been placed in humans since 1965.

In 1984, a dying infant lived for three weeks with a baboon heart inside her chest.

Pig-to-human transplant work has raised concerns about donor pigs' living conditions.

Listen to why thousands of donated human kidneys are thrown away annually, even as thousands of people are awaiting a kidney transplant.

Transplant organs don't always last a lifetime—that's where retransplants come in

How long a transplanted organ lasts depends on a variety of factors including the type of organ and the health of the recipient. Sometimes organs can last many decades, but other times people may need retransplants, which means another transplant following a previous one. Retransplants are most common with kidneys.

Explore different pig-to-human xenotransplantation possibilities, including using pig pancreatic cells for treating diabetes.

How personalized gene-editing saved a baby's life

KJ Muldoon had a 50% chance of surviving a genetic mutation until doctors developed a one-of-a-kind gene-editing therapy. In an interview with one of the researchers behind the treatment, learn what it will take to make personalized genetic medicine possible for everyone.

A clinical trial is underway in 2026 to help kidney transplant recipients avoid a lifetime of immunosuppressing drugs

This later-stage clinical trial, in Chicago and Taiwan, evaluates the efficacy and safety of a new cellular therapy that may be swapped in for immunosuppressing drugs among kidney transplant recipients. The study randomizes people to either receive standard immunosuppressants or this cellular therapy and fewer immunosuppressants. It only includes kidney transplant recipients receiving organs from live donors so transplant surgery timing won't hinge on the unpredictable schedule of performing surgery and follow-up care when a donor dies.

Watch this video letter (via Facebook) from a kidney recipient to his donor

A kidney recipient named Justin reads a letter he wrote to his deceased donor about how the person's generous kidney donation saved his parents from having to watch him suffer and his brother from having the pressure of perhaps being his only shot at a life-saving transplant.

Pig organ transplants are apparently kosher—you just can’t eat them

Science writer Mary Roach speaks with journalist Terry Gross about her latest book, “Replaceable You: Adventures in Human Anatomy” and discusses topics including why pig organs have become of such interest and what religious leaders have told her about pig organs and compliance with Jewish dietary law.

Living donations most commonly involve a kidney or part of a liver

In 2023, more than 6,900 transplants were made possible thanks to living donors. Living donation is when a living person donates an organ or part of an organ—usually one of their two kidneys or part of the liver, since that organ can regenerate in a healthy person. Much more rarely, living donors donate other organs. Living donations often occur when someone wants to ensure a loved one has certainty that they will quickly receive a needed organ.

US federal researchers are blocked from putting certain human cells in animals

In 2015, US policymakers put a halt to any government-funded work that would insert human stem cells into animals. The reasoning was that human cells might spread through the animal's body and perhaps to its brain, blurring the line between humans and nonhumans. The ban remains in place today even as gene-edited pig parts are being placed in humans.

NSF-funded research into matching algorithms improved the success of organ transplants

Investigations in game theory, including concepts focused on creating mutually beneficial partnerships—matching theory—led to the design of computer systems that efficiently matched kidney recipients and live donors, resulting in higher-quality matches. By 2019, these matching algorithms were used for multi-organ exchanges.

Donated hearts remain viable three times longer now with new tech

Advances in organ perfusion systems have significantly lengthened the amount of time donated hearts can remain viable for transplant, expanding the possibilities for donor organs to wider geographic areas. "Heart in a box" devices, developed in recent years, enable effective oxygen flow in the donor heart during transport, which means that hearts can now travel farther to potential recipients and still be in good condition.

Cross-species transplantation has been attempted in medicine for more than 300 years.

Gene therapy, a hope of the Human Genome Project, has successfully treated a baby born with a rare urea cycle disorder that causes toxic ammonia level buildup.

Pigs are of particular interest for xenotransplantation because they are close to human size, are easily raised in captivity, and have large litters.

Transplanted organs can be rejected by the body immediately, months after transplant, or slowly over years

Organ rejection remains a huge challenge for organ transplant recipients. Rejection occurs when a recipient's immune system identifies a transplanted organ as foreign and attacks it. Recipient-donor screening processes try to match antigens to help reduce this risk.

Scientists using gene therapy recently managed to regenerate retinal cells in the lab—a breakthrough for mammals that could potentially lead to future treatments for human retinal diseases.

Tech entrepreneur Bryan Johnson's mission to live forever

Johnson has invested millions of dollars into developing a biohacking program he believes will extend his life beyond typical expectations, relying on medical professionals to reduce his "biological age." Most notably, he drew significant public attention with reports of blood-swapping with his teenage son.

3 US maps illustrate transplants, donors, and organ waitlist additions—by state.

As of 2025, perfect synthetic replication of natural organs remains elusive

Advancements such as 3D printing muscles, performing vaginal reconstruction with colon tissue, and growing organs in a lab have shown promise, but artificial options and transplanting substitutions continue to exhibit functional and performance limitations compared to their natural equivalents.

Artificial intelligence may improve organ donation systems—and even organ health

Mayo Clinic transplant experts suggest that artificial intelligence could potentially improve organ donation systems in several ways, including better identifying patients most at risk for organ rejection, enhancing donor-recipient matching, and helping to avoid organ transplant needs by identifying health issues earlier.

Pig brain cellular activity was restarted hours after death in study published in 2019

Yale University scientists restored basic cellular activity and circulatory function in pig brains about four hours after death with a synthetic cocktail of preservatives and nutrients. This work— which didn't restart electricity activity in the brain or consciousness—could help advance future human stroke and brain injury treatments.

Several years after the English law changed, organ donation rates haven't improved

A 2024 analysis found that several years after England changed its organ donation system to an opt-out donation system there was no improvement to the country's organ donation rates, perhaps highlighting the need for better understanding and education around the law.

The scientist that biohacked a buff frog

If a tree frog was injected with a DNA mixture containing follistatin, a gene that may influence muscle growth, would it become buff? Josiah Zayner hopes so. By learning how to biohack animals, he hopes people are one step closer to feeling more comfortable "whipping up DIY gene therapy."

The global xenotransplantation market may already be valued at more than $13B.

In 2023, the FDA approved gene therapy for sickle cell disease, enabling one-time infusion bespoke treatments that use a patient's own stem cells to effectively cure a painful condition that disproportionately affects people of African American descent.

Organ transplants can come with a price tag of more than $2M without insurance

According to 2025 report data that was graphically represented by Statista, average costs for organ transplants can be as steep as $2.3M for a double lung transplant and $1.9M for a heart. These figures are based on what was actually charged to insurance companies—not what individual patients paid. Following the actual transplant there are also additional costs associated with the procedure, including lifelong immunosuppressant drugs.

Leonard Thompson was the first human to receive an insulin injection for diabetes

In January 1922, the 14-year-old was the first person to receive an insulin injection to treat diabetes, just months after insulin was isolated in dogs and used to treat their induced diabetes. Thompson had an allergic response to an apparent impurity in the injection, but his second dose, 12 days later, was a success.

When was the first blood transfusion?

In the 1600s, an English doctor transferred the blood from one dog to another via quills. The procedure ended when one of the dogs died. This article details the early days of blood transfusions, which turned toward humans shortly after the 1666 dog experiment and involved putting the blood of a sheep into a human recipient (who reportedly survived the encounter).

'Donation after circulatory death' is on the rise

This occurs when a patient in a coma is on life support and family members agree to donate the organs. Watch this video about a 2025 New York Times investigation that identified 12 instances across nine states of bungled or premature attempts to retrieve organs from people whose families had authorized withdrawal of life support.

The first successful IVF pregnancy was in the United Kingdom in 1978

Gynecologist Patrick Steptoe and his collaborator Robert Edwards, a biologist, attempted to fertilize a human egg cell in a petri dish 101 times before finally succeeding. This resulted in the birth of Louise Brown—at the time referred to as a "test tube" baby—in 1978, who was born into the spotlight.

Epigenetic editing—altering gene expression by removing or adding chemical groups on DNA—is making significant strides in the lab, even lowering cholesterol in monkey experiments by about 70%. (Free w/email.)

A physician with a rare and deadly disease saved his own life by identifying an existing medication that he repurposed for his condition, and now he's using AI to try to do the same for other patients.

England changed to an organ donation opt-out system in May 2020

A law that went into effect in May 2020 in England changed the country's organ donation regulations, reflecting public support for organ donation. Now, adults are typically presumed to have agreed to donate their own organs upon death unless they declare they're refusing to donate organs (or their family opts them out).

Biotech is trying to boost drug production efficiency—using chicken eggs

A company called Neion Bio is genetically engineering birds in a bid to produce medical compounds, a herculean task that scientists have struggled with for decades. The US FDA has approved only one chicken-derived drug in the past—an expensive treatment for a rare liver disorder. (Some users may encounter a paywall.)

Eight British children have been born via mitochondrial replacement therapy

In July 2025, a decade after British lawmakers signed off on allowing three-parent IVF, scientists announced that eight healthy babies had already been born using this approach. The news was included in a pair of research articles published in a peer-reviewed journal that noted the oldest kids were already more than two years old, and that they were hitting developmental milestones as expected. (Some users may encounter a paywall.)

60 years after seeing Henrietta Lacks as a patient, her doctor still remembered the unique cervical tumor that gave rise to the 'immortal' cell line now commonly used in biomedical research—it was purple, shiny, and soft—an appearance he said is very different from a typical tumor.

Genetic engineering will change everything forever

Designer babies, the end of diseases, genetically modified humans that never age. Outrageous things that used to be science fiction are suddenly becoming reality. As scientists increasingly understand how specific genes cause disease, the possibility of engineering our genes to not only "fix" problems but enhance our natural ability grows.

Prehistoric hunter-gatherers performed amputations and appear to have provided post-op care, according to analysis of a recent fossil discovery from almost 31,000 years ago.