Moon children.

This programme explores xeroderma pigmentosum (XP), a devastating illness which means any exposure of the skin to sunlight can lead rapidly to skin cancer. We meet two children with the condition and get an insight into their lives. However XP has proved to be invaluable to medical researchers in helping them to find the genetic components of cancer; forerunners in this field such as Henry Lynch, Richard Setlow and James Cleaver describe their work. The implications for the treatment of other kinds of cancer leading on from this research are discussed including the development of a new drug to help cancer patients who have become chemotherapy-resistant. In the meantime XP patients have to have frequent operations to remove cancerous growths from their skin and scientists are hoping to develop a DNA repair cream to prevent cancerous skin growth. Such a cream could also help those suffering from skin cancer due to over-exposure to UV rays.