In mice with progeria, aging runs as if in fast-forward. Scientists gave them a switch that turns on the protein Δ133p53α, a shortened version of p53. This protein works like a brake pedal: it slows cellular aging but does not switch off cancer protection.
After the brake was switched on, the mice's aortic walls and skin thickness recovered, inflammation levels dropped. The spine curved less often. The mice lived longer: median life span rose from 349 to 387 days. Cancer did not increase.
In human skin, levels of Δ133p53α fall with age, while levels of the protein that triggers aging rise. So we have this brake too, but over time it is released. If we can learn to press on it again, we could slow aging without the risk of tumors. Mice have already shown that it works.
Δ133p53α got its name because it starts at the 133rd amino acid residue of p53, while the letter Δ (delta) means a deletion of the first 132 amino acids. This isoform occurs naturally in human cells, and its levels fall with age.
In Aldous Huxley's novel Brave New World, people age more slowly thanks to genetic manipulation. Work on Δ133p53α is a step in the same direction, but without the dystopian undertone: the goal is not immortality but a longer healthy life.
Not published on arXiv. Here are its page, the PDF and the formalization: you can check it yourself, not only read our account.