A 'zombie gene' has been discovered which makes elephants virtually immune to cancer. What's more, experts believe that producing drugs that mimic this gene could lead to a breakthrough in cancer prevention for humans.

One in six humans die from cancer, but less than one in 20 captive elephants are killed by the disease. That's despite having about 100 times as many potentially cancerous cells.

Researchers have discovered that elephants have evolved a way to make LIF6 - a dead gene in mammals - come back to life. This is what makes the largest living land mammals almost immune to cancer.

Now scientists hope the breakthrough could lead to better treatment for people with cancer.

Researcher Dr Vincent Lynch, from the University of Chicago, US, said: "Elephants get cancer far less than we'd expect based on their size, so we wanted to understand the genetic basis for their cancer resistance.

"We found that elephants and their relatives have many non-functioning copies of the LIF gene, but that elephants themselves evolved a way to turn one of these copies, LIF6, back on."

In response to DNA damage, the elephant version of a tumour-suppressing protein prompts 'zombie' LIF6 to efficiently kill cells poised to become cancerous.

Researchers were able to isolate elephant-specific genetic variations and focus on which one could be associated with cancer suppression.

Elephants aren't the only animals that have evolved cancer resistance. Dr Lynch said: "Species like whales, bats and naked mole rats don't have these zombie LIF genes, which means that they have evolved cancer resistance using a different strategy and there are many ways animals can combat cancer."

Now Dr Lynch and his colleagues want to apply the elephant's strategy for cancer resistance to human cancer biology.

He added: "Maybe we can find ways of developing drugs that mimic the behaviours of the elephant's LIF6 of getting cancerous cells to turn on their existing zombie copies of the LIF gene."