Biologists say they’ve identified a gene that protects against cancer by suppressing cells’ ability to divide—making us age faster in the process.

The findings suggest that a fundamental tradeoff between long life and cancer protection is built into our bodies, the scientists said. The work also indicate aging may in some sense be programmed, they added, which some researchers have theorized before.

The conclusions emerge from three papers published online in the research journal Nature this week.

The studies were aimed at explaining why stem cells, “master” cells that can develop into a variety of different cell types, lose the ability to divide and generate new cells with age.

Experiments found that a molecule called p16INK4a, and a gene that produces it, limits such cells’ regenerative abilities, the researchers said.

The apparent benefit of this is to head off cancer, which involves runaway cell multiplication. The molecule was already known to suppress cancer.

The drawback is that slowed cell division is linked with aging, according to the scientists.

The authors of the studies found that that the gene’s activity increases as stem cells in three mouse tissues lose their ability to self-renew.

The teams genetically engineered mice that lacked p16INK4a and then examined them when they got old. Progenitor cells in the rodents clung onto their youth and didn’t show the normal decline in proliferation with age, they said.

Sean Morrison of the University of Michigan in Ann Arbor, Mich. and colleagues studied progenitor brain cells in mice. Norman Sharpless of the University of North Carolina School of Medicine in Chapel Hill, N.C. and his team studied progenitors in the pancreatic islets that make insulin-secreting beta-cells. David Scadden of the Harvard Stem Cell Institute in Boston and his group examined bone marrow cells that make blood.

The work also suggests type 2 diabetes might partly result from a failure of cells in the pancreatic islets to renew with ageing, the researchers said. Thus, they added, blocking this protein in certain tissues might combat certain effects of ageing.

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