The branches · Lifespan and repair · could move a stage within 1 to 5 years

Partially resetting cells reverses ageing in a living animal

Shown in animals

Four genes can turn an adult cell back into something like an embryonic one. Switched on briefly and then off, in a live animal, they turn back some of the marks of age without erasing what the cell is. In 2016 mice with a premature-ageing disease lived longer when this was done to them, and in 2020 old mice regained sight after the nerve from the eye was reset. It is the most direct attempt yet to reverse ageing rather than slow it. The first person was given it, in one eye, in June 2026, with no result yet reported.

What would count

A living animal given a brief, controlled dose of reprogramming genes afterwards has a measured marker of biological age (an epigenetic clock, a restored tissue function) moved towards youth, compared with untreated controls, in a peer-reviewed report. The first-human rung needs the same in a person.

Who settles it: Peer-reviewed reports; the trial registry entry and report when the first person is treated

Where it stands

Shown in animals. Reached on 15 December 2016, on the record of doi.org. Could move a stage within 1 to 5 years.

The last reading

Once a week every upgrade is read against the news, against what would count above. Open a line to see what that week held. Every reading of this upgrade is on this week's reading.

  • 16 October 2026 Nothing new

    Nothing in the window. Life Biosciences' trial of ER-100 in two optic nerve diseases, which the entry's notes say dosed its first participant on 2026-06-09, has reported no measured result; the searches found only the company's 2024 and 2025 animal presentations and secondary coverage of the trial's start. The first-human rung needs a measured marker moved toward youth in a person.

Notes

The record is the 2016 Salk Institute report of partial reprogramming in live mice. The 2020 Harvard report that restored vision in old mice by resetting cells in the eye is the clearest reversal of a lost function. A company founded on that work announced on 9 June 2026 that the first participant in its trial for two optic nerve diseases had been dosed. Under this entry's test the first-human rung needs a measured reversal in a person, not a dose, so the entry stays at shown in animals until the trial reports; if John would rather count the dose, the stage moves to first human on the company's own release.