Vitiligo is an autoimmune condition, in which the immune system attacks the pigment-producing cells of the skin, leaving behind pale white patches. Although not dangerous in itself, vitiligo can be disfiguring, causing a great deal of distress to people suffering from it. There are treatments available for vitiligo - these include topical creams that suppress the immune attack on skin cells, and phototherapy, which uses UV light. However, these treatments are time- and effort-consuming, particularly if large areas of the skin are affected. Another problem is that they only work temporarily - in many patients, the disease returns when the treatment is stopped. Crucially, the disease tends to return in the same patches of skin where it first appeared - prompting a team of researchers to wonder whether this property may lead to an explanation as to how the disease occurs, and even a potential cure. To find out more, I, Isabelle Cochrane spoke to Prof John Harris...