Another step towards reducing rates of cervical cancer - the leading cause of cancer mortality in women.

Otago University researchers have pinpointed a protein known as E7 that causes high rates of the cancer from the HPV virus.

They've found that for 10-20 percent of people, E7 makes it much easier for them to contract cervical cancer, if the virus doesn't clear within 1-2 years.

Professor Merilyn Hibma told Larry Williams it's a significant find.

"What this is really about is the burden of disease in women who have already been exposed to the virus and have persisted in sections that may lead to cancer or to the cancer itself," she said.

Professor Hibma said the next step is to understand how the protein works.

"What we need to really understand is the fundamental, underlying mechanisms of how is this working. Then we have the potential to try and intervene with therapy."

LISTEN ABOVE: Professor Merilyn Hibma spoke with Larry Williams