If mobile phones can cause cancer, it has the potential to be another tobacco or asbestos.
The World Heath Organisation's (WHO) Agency for Research on Cancer conference in Lyon, 31 experts concluded that there was a "possible" link between mobile phones and a type of cancer called Glioma.
The WHO has five rankings ranging from "carcinogenic" to "probably not carcinogenic" with "possible" in the middle.
The WHO is not saying there is a link - but is not ruling one out either!
There are 5.3 billion mobile contracts around 77% of the World's total population.
A billion new handsets are sold every year.