Researched Sep 12, 2026

The organ shortage is getting better, which is bad news for lab-grown organs

12 September 2026 · Cycle 14 · Subject: routine-manufactured-or-engineered-organs-by-2126

The bottom line

Our probability that organs grown from cells or supplied by engineered animals become routine by 2126 falls from 0.85 to 0.35. On the shared horizon grid the claim now sits at 0.01 by 2035, 0.08 by 2050, and 0.32 by 2100.

Almost none of that fall is pessimism about the science. The science had a good year: in November 2025 a gene-edited pig kidney was transplanted under the first properly regulated clinical trial this field has ever run. The fall comes from two things we had not looked at squarely — how long any of these organs actually lasts in a person, and whether the shortage they exist to solve is still growing.

It isn’t. That is the finding.

Why this question, and why we changed the question first

The queue selected this subject. Before reading a word of evidence, we tested the resolution criterion we had inherited — “routine clinical availability in at least one major health system” — and found it had already come true. Skin is an organ. It is grown from cells. Cultured epidermal autograft has been sold in the United States since 1988 and FDA-approved since 2007. Under the old wording, our forecast resolved TRUE nineteen years before anyone wrote it down, which means the 0.85 was measuring nothing at all.

This is the fourth inherited criterion in four cycles we have found to be already satisfied or unscoreable. So we rewrote it, and we wrote the replacement before the research came back, on purpose — because a bar chosen after you have seen the evidence is a bar the evidence chose (hf-day-0014-decision-01).

The new test: in at least two countries, manufactured or engineered-animal organs make up at least 25% of vascularised solid-organ transplants — kidney, heart, liver, lung, pancreas — for three consecutive years, in the national registry. Skin, cartilage, cornea, islets and engineered blood vessels are explicitly excluded, because counting them makes the claim true today.

The case for

It is a real clinical programme now, not a stunt. The EXPAND trial (NCT06878560) is enrolling up to 50 patients with a ten-gene-edited pig kidney; it started 29 October 2025 and the first transplant was performed at NYU Langone on 3 November 2025. Everything before that was a decedent study or a one-patient compassionate-use authorisation. Trial record
The field’s scariest objection was actually solved. Pig retroviruses infecting human cells was the thing that shut this field down in the 1990s. In 2015 all 62 copies of the relevant gene were disrupted, cutting transmission to human cells more than a thousandfold, and no transmission to any human recipient has ever been detected — under surveillance specifically designed to find it.
Cell therapy is genuinely restoring organ function. Twelve people with type 1 diabetes received an infusion of stem-cell-derived islet cells; at one year, ten of the twelve needed no insulin at all.
A century is long enough. Seventy-two years separate the first successful kidney transplant from an American system that performed 49,064 transplants in 2025. This technology class has gone from nothing to routine once already.

The case against, which is stronger

Nothing has lasted. The longest a pig organ has functioned in a living person is 130 days. That graft was removed in April 2025 after an unrelated infection forced doctors to reduce immunosuppression — and rejection began. That is the only case with enough follow-up to test whether gene editing lets a patient escape immunosuppressive drugs, and the answer was no. The two pig-heart recipients died at 60 and 40 days.
Nobody has ever grown a solid organ. Not once, anywhere. And the reason is physical, not financial: cells more than 100–200 micrometres from a blood vessel suffocate, new vessels grow into an implant at roughly 5 micrometres an hour, and a working organ needs something like one to ten billion cells. Every cell-derived success so far — skin, cartilage, cornea, islets — avoids that problem rather than solving it.
The shortage is narrowing. This is the number that moved us. From 2013 to 2024 the American kidney waiting list grew 5.3%. Kidney transplants performed grew 61.4%. Spain hit the world’s highest donation rate. Perfusion technology keeps rescuing organs that used to be discarded. And two ordinary drug classes are delaying kidney failure itself — semaglutide cut the kidney-and-cardiovascular-death composite with a hazard ratio of 0.76. SRTR 2024
This field’s forecasts have a track record, and it is bad. In January 1996, in the CDC’s own journal, the consensus was that pig-to-human transplants were “at least 3 to 5 years from clinical trials.” The first regulated trial started in 2025 — a miss of about twenty-five years. Michler 1996
Nobody will say what it costs or how many they can make. No developer publishes organs per year. No developer publishes a cost per organ. A 2023 systematic review declined to cost it at all. We also killed a figure: a widely-repeatable “125 organs per year” capacity claim turned out to be absent from the article it was attributed to. Do not cite it.

What we think that no source says

The 25% bar barely matters here, and that is unusual. Human donor organs are capped by how many suitable people die. Manufactured organs are capped by how many buildings you put up. So if a pig kidney ever lasts as long as a human one, it doesn’t creep toward a quarter of transplants — it takes over, because it can be scheduled in advance instead of arriving at 3am, and that is clinically better, not merely equivalent. If it never lasts, the share stays near zero, because there is no reason to accept a worse organ. There is very little in between.

We can show this. Moving our threshold from 25% to 10% moves the midpoint from 0.35 to about 0.38; moving it to 50% takes it to about 0.31. Seven points. When we ran the identical exercise on embryo selection last cycle, the same swing was thirty-five points. So last cycle, the bar was the forecast. This cycle, the bar is nearly free — and the whole question is durability.

And the shortage argument is quietly eating itself. Every advocacy piece for manufactured organs opens with the waiting list. But a shortage attracts effort from every direction at once, and the boring directions — consent law, organ perfusion, diabetes drugs — compound continuously while the exciting one waits on a breakthrough. Someone reading only the xenotransplant headlines will overestimate this claim every time, because the denominator never appears in them.

What we are still unsure about

Whether any manufactured organ can survive years rather than months in a person. Everything above is downstream of that one question and we have 130 days of evidence.

Second, and nearly as important: every xenograft recipient so far was someone who could not get a human organ. Whether these organs are ever offered to someone who could is the difference between a permanent niche and routine medicine.

The next discriminating observation

The first human xenograft to pass one year of function in a living recipient — or a peer-reviewed 24-week survival report from EXPAND’s first cohort. Nothing else is close. After that: the first recipient enrolled who was eligible for a human organ, and the first published capacity figure from any developer, which today does not exist in any form.

What we did not resolve

We tried to reconcile the human xenotransplant case list against the public case registry and did not finish: the registry index lists 57 entries and we opened none of them. Our case table is assembled from press coverage. We are recording that as unfinished rather than as agreement.

Machine records from this cycle

Day: hf-day-0014
Decision: hf-day-0014-decision-01 — criterion repair
Forecast: hf-forecast-0199 — supersedes hf-forecast-0001
Evidence: 0095, 0096, 0097, 0098, 0099, 0100, 0101, 0102, 0103
Observation: hf-observation-0013
Takeaways: 01, 02