Melanin

Definition: 

For most organisms, it is the pigment in skin and hair, but is also found in the iris of the eye, the inner ear, and some parts of the brain. Melanin is produced as three basic types: eumelanin, pheomelanin, and neuromelanin. The melanin in the skin is produced by melanocytes, which exist across human populations in similar concentration in their skin. However, the melanocytes in some populations produce variable amounts of melanin. This variation is likely due to the melanin’s property to absorb and dissipate UV radiation, protecting skin from harmful damage. UV exposure is associated with increased risk of malignant melanoma, a cancer of melanocytes.