Complexion matters

摘要

The most common environmental risk factor for skin cancer is overexposure to sunlight. But is protecting skin from the sun enough to prevent cancer? In this issue, Mitra et al.address this question using mice that are genetically similar to humans who have red hair and fair skin or to dark-skinned or albino individuals. They find that the often deadly skin cancer melanoma occurs more frequently in 'redheaded' mice than in the other two groups, owing to mechanisms that are unrelated to exposure to ultraviolet light.rnColours of skin, eyes and hair vary widely among humans. This variation is controlled by the amount and ratio of two forms of the pigment melanin (the red-yellow pheomela-nin and the brown-black eumelanin).