Scientists discover how ultraviolet rays trigger skin cancer. They may also have found a way to stop skin cancer in its tracks using a gene target. Melanoma is a cancer of the skin pigment cells, which are called melanocytes. Melanoma only accounts for around 1 percent of all skin cancers, yet it is responsible for most skin cancer-related deaths. Melanomas can occur anywhere on the skin, but they are most likely to develop on the chest and back in men and on the legs in women. Other common sites for melanomas include the neck and face. When exposed to ultraviolet (UV) radiation, melanocytes release melanin, a dark brown to black pigment that protects the skin from the sun’s rays. But in melanocyte stem cells that have reached and exceeded a threshold of genetic mutations, activation by sun exposure causes them to grow a tumor. Skin cancer research professors have identified a way to prevent melanomas that are caused by the mutated stem cells. When exposed to ultraviolet (UV) radiation, melanocytes release melanin, a dark brown to black pigment that protects the skin from the sun’s rays. But in melanocyte stem cells that have reached and exceeded a threshold of genetic mutations, activation by sun exposure causes them to grow a tumor. Scientists have identified a way to prevent melanomas that are caused by the mutated stem cells.