Naked mole rats almost never get cancer and routinely live more than thirty years — roughly ten times longer than any other rodent their size — and researchers in October 2025 finally identified one of the key mechanisms: a handful of tiny mutations in a single gene that powers DNA repair in the mole rats but suppresses it in humans

If you handed a biologist a small, hairless, buck-toothed rodent the size of a sausage and told them it would outlive their golden retriever, their last car, and possibly their mortgage, they would assume you were lying. Every other rodent of the naked mole-rat’s approximate body size — house mice, hamsters, gerbils, rats, voles — lives between two and four years under typical conditions. The animals are small. They have fast metabolisms. They reproduce quickly and die quickly. The biological calculus that governs small-rodent lifespan is one of the older and better-established patterns in evolutionary biology, and the naked mole-rat is, by every available measure, the single most dramatic exception to it. The species lives ten times longer than its body size predicts. It does so while resisting essentially every age-related disease that kills its rodent relatives. It dies, when it eventually does, with no apparent increase in mortality risk over the course of its multi-decade adult life — a pattern the USC gerontologist Caleb Finch has described as the first confirmed case of negligible senescence in any mammal.

According to SciTechDaily’s coverage of the October 2025 paper published in Science by Yu Chen and colleagues at Tongji University, the new finding traces a substantial portion of this longevity to four specific amino acid substitutions in a single protein called cGAS. The protein, whose full name is cyclic guanosine monophosphate-adenosine monophosphate synthase, is present in essentially every animal on Earth. Its standard function, well-understood in humans and mice, is to act as a kind of cellular alarm system: it detects fragments of DNA that have appeared outside the cell nucleus (often a sign of viral infection or cellular damage) and triggers the innate immune response. In humans and mice, however, cGAS has a second, less well-known function inside the cell nucleus, where it actively suppresses one of the most important DNA repair pathways — homologous recombination, which is responsible for fixing the kind of double-strand DNA breaks that, if left unrepaired, drive both cancer and biological aging.

What the four amino acid changes do

The naked mole-rat version of cGAS differs from the human version by four specific amino acid substitutions. In molecular terms these are tiny changes — four positions out of the protein’s several hundred — and the substitutions do not change what the protein fundamentally does. They change how long it lasts. As reported by Chemical & Engineering News’s coverage of the Chen et al. study, the substitutions reduce the rate at which cGAS gets tagged with ubiquitin (the cellular signal for protein degradation), which means the protein persists in the cell at higher concentrations for longer periods after DNA damage occurs. The increased abundance changes the protein’s behavioural relationship with the DNA repair machinery. Instead of suppressing homologous recombination as the human version does, the naked mole-rat version interacts more strongly with two essential repair proteins called FANCI and RAD50, and the net effect is that homologous recombination is enhanced rather than inhibited. The DNA gets repaired more efficiently. The damage that accumulates with age accumulates more slowly. The cells stay healthier for longer.

The Chen team tested the mechanism by removing cGAS from naked mole-rat cells in the laboratory, which produced a sharp increase in DNA damage — confirming that cGAS was responsible for the enhanced repair in the species. They then took the experiment in the opposite direction, engineering fruit flies to carry the four naked mole-rat amino acid substitutions in their version of the cGAS protein. The modified flies lived longer than control flies with the unaltered protein. This second result is the substantively interesting one for the longer-term human relevance of the finding: the mechanism is not specific to the naked mole-rat’s unique cellular environment. Engineering the four mutations into a different species’ cGAS produces a measurable longevity effect in that species too.

One of several mechanisms

The cGAS finding is not, by anyone’s account, the complete explanation for naked mole-rat longevity. As described in ScienceDaily’s coverage of the Chen et al. paper and its broader context, the species has been studied for several decades, and multiple distinct biological mechanisms have been identified that appear to contribute to the unusual lifespan. A 2023 paper from Vera Gorbunova’s laboratory at the University of Rochester established that naked mole-rats produce approximately five times more high-molecular-weight hyaluronic acid (HMW-HA) than other mammals, and that transferring the gene responsible for this into mice produces healthier, modestly longer-lived mice — a 4.4 percent increase in median lifespan, with substantially reduced tumour incidence. Earlier work has identified unusual stability in the species’ telomeres, unusual accuracy in its ribosomes, unusual robustness in its protein-quality-control systems, and unusual cellular tolerance for the low-oxygen environment of its underground burrows. The senior author of the new Tongji paper, Zhiyong Mao, has emphasised in correspondence with C&EN that the cGAS finding is “merely one piece of the puzzle” and that the naked mole-rat’s longevity “is probably the result of several concurrent adaptations.” The species, in this view, is not protected by a single mechanism but by multiple overlapping defences that have evolved together over the approximately 73 million years since its lineage diverged from other rodents.

What this means for human longevity research

The practical implications for human medicine are substantial in principle and uncertain in timeline. Per a USC Leonard Davis School of Gerontology summary of the broader scientific reaction, some commentators have estimated that successful translation of the cGAS mechanism to humans could extend human lifespan by approximately 12 years — a substantial figure that would represent the largest single longevity gain ever attributed to a specific molecular intervention. Two approaches are currently under consideration: pharmacological modulation of cGAS using small molecules that would mimic the effect of the naked mole-rat substitutions, or direct gene editing using CRISPR-class technologies to replace the four amino acids in the human cGAS gene with the mole-rat versions. Both approaches face substantial technical, regulatory, and ethical hurdles before they could be tested in humans. Neither is likely to produce a clinical application within the next decade. The naked mole-rat itself, however, will continue to live for up to 37 years in research colonies around the world, reproducing well into old age, declining to develop the cancers that should statistically have killed it many years earlier, and providing molecular biologists with the only available living example of a mammal that appears, by every available measure, to have substantially solved the problem of biological ageing.