Emerging role of nitric oxide in cancer

The small molecule nitric oxide has generated an exponential amount of rese arch since its identification as a biological messenger in 1987. It is a fr ee radical, the actions of which are diverse, and many are still poorly und erstood. An area of great interest is the role of nitric oxide in the growt h and metastasis of solid tumours, where it seems to have a complex action including both inhibitory and tumour-promoting activity. Over 28 000 resear ch papers have been written on nitric oxide, with only a minority concentra ting on the head and neck. In this review, we give a brief history of this fascinating molecule, concentrating on its possible interest to oral and ma xillofacial surgeons.