CHICAGO — Elephants hardly ever get cancer, and scientists have finally figured out why.

According to research from the University of Chicago, over 17% of people worldwide die from cancer, compared to less than 5% for elephants, even though they have 100 times as many potentially cancerous cells.

One reason for this is they have over 20 copies of the tumor suppressor gene p53 that stops DNA damage from turning into cancer, while humans and other animals only have one.

Because the cells died as soon as damage was detected, there is zero risk of them ever becoming cancerous.

The study found that p53 can also trigger an inactive pseudogene in elephants called LIF6 to come back to life. When cell damage is detected by p53, it activates the LIF6 gene, which in turn produces a protein that pokes holes in the target mitochondria and causes it to die.

This genetic resistance to cancer isn't just seen in elephants. Smaller critters like naked mole rats and grey squirrels also have mechanisms that keep them tumor-free.

By studying how these animals' genes work, scientists are hoping to figure out how to prevent or treat cancer in humans.