The headlines were clear enough - a major study has confirmed that mobile (cell) phones don't cause cancer - and yet some of the researchers aren't quite so sure. The Interphone study has concluded that the phones do not cause brain tumours such as glioma, even after 10 years' usage, or among the heaviest users. However, not everyone agrees with the finding, including some of the 21 scientists who helped put the study together. Dr Elisabeth Cardis, of the Centre for Research in Environmental Epidemiology in Barcelona, who led the study, said: "Overall, my opinion is that the results show a real effect." Another Interphone researcher, Bruce Armstrong from the University of Sydney, said: "There is evidence that there may be a risk; Interphone has made that a little stronger." In fact, Interphone did discover that long-term usage increased the chance of glioma by 40 per cent, but dismissed the risk because of possible biases and errors. Interphone has been beset by controversy almost from the day it was set up in 2000. Mobile phone manufacturers have partly funded the project - and have contributed around 5.5 million euros - and there have been concerns that this has affected the study's independence. The scope of the project was also questioned, as it has left out children and adolescents, the most vulnerable group that is more susceptible to brain tumours. Finally, Interphone was supposed to have published its findings four years ago, and some commentators suspect the delay was because of major disagreements among the researchers. Judging by the comments that some of the scientists have made in public, this may well be the case. (Source: International Journal of Epidemiology, 2010; 1-20; doi: 10.1093/ije/dyq079).