Inflammation is like the hand of a biological clock: the further it is pushed, the faster the body ages. Scientists have found a way to read that hand through chemical marks on DNA. They picked 127 genes that switch on during inflammation and learned to predict a person's age from their state.
The model was trained on blood samples from healthy people, and it guessed age with an error of about six years. Then it was tested on tumor tissues. It turned out that cancer cells look older than their years, and cells next to a tumor look older than healthy ones. It is as if the disease pushes the clock's hand forward.
Then the scientists ran the reverse experiment: they returned cells to a young state through reprogramming. The clock's hand moved backward, and the models showed rejuvenation. This means inflammatory marks do not simply accumulate; they can be erased.
Now any researcher can build such a clock for their own genes using the web tool GeneClock Studio. Instead of thousands of random marks, you can take a small set of related genes and track a specific process, such as inflammation. This opens the way to clocks that show not just age, but the contribution of individual aging mechanisms.
In the cancer set of 39 tumor types, samples from a 112-year-old woman had to be excluded to avoid skewing the statistics.
Not published on arXiv. Here are its page, the PDF and the formalization: you can check it yourself, not only read our account.