after three decades of painstaking research, a team of American researchers has at last been able to establish a direct link between smoking and lung cancer. Mikhail F Denissenko, Annie Pao, Moon-shong Tang and Gerd P Pfeifer have reported in Science (Vol 274, No 5286) the first direct evidence showing that a chemical found in cigarette smoking causes genetic damage in lung cells that is identical to many malignant tumours of the lung. The finding is significant as it could topple more than three decades of denials by tobacco companies and provide plaintiffs with the