Retrospective epidemiological data have indicated that cutaneous malignant melanoma may arise as a consequence of intense, intermittent exposure of the skin to ultraviolet radiation, particularly in children, rather than from the cumulative lifetime exposure that is associated with other forms of skin cancer^{1, 2, 3}. Here we use a genetically engineered mouse model to show that a single dose of burning ultraviolet radiation to neonates, but not adults, is necessary and sufficient to induce tumours with high penetrance which are reminiscent of human melanoma. Our results provide experimental support for epidemiological evidence that childhood sunburn poses a significant risk of developing this potentially fatal disease.

1. Laboratory of Photobiology and Photoimmunology, Departments of Dermatology and Immunology, George Washington University Medical School, Washington DC 20037, USA
2. Laboratory of Molecular Biology, National Cancer Institute, Bethesda, Maryland 20892-4255, USA
3. Laboratory of Pathology, National Cancer Institute, Bethesda, Maryland 20892, USA
4. Pathology/Histotechnology Laboratory, Science Applications International Corp., National Cancer Institute at Frederick, Maryland 21702-1201, USA
5. Department of Dermatopathology, Armed Forces Institute of Pathology, Washington DC 20306, USA

Correspondence to: Glenn Merlino² e-mail: Email: gmerlino@helix.nih.gov