Micrograph of<unk>  pigment (light refracting granular material—center of image) in a pigmented melanoma. Micrograph of the epidermis, with<unk>  labeled at left.<unk>  (; from ) is a broad term for a group of natural pigments found in most organisms.<unk>  is produced through a multistage chemical process known as melanogenesis, where the oxidation of the amino acid tyrosine is followed by polymerization. The<unk>  pigments are produced in a specialized group of cells known as melanocytes. Functionally,<unk>  serves as protection against UV radiation. There are five basic types of<unk> : eumelanin, pheomelanin, neuromelanin, allomelanin and pyomelanin. The most common type is eumelanin, of which there are two types— brown eumelanin and black eumelanin. Pheomelanin is a cysteine-derivative that contains polybenzothiazine portions that are largely responsible for the color of red hair, among other pigmentation. Neuromelanin is found in the brain. Research has been undertaken to investigate its efficacy in treating neurodegenerative disorders such as Parkinson's. Allomelanin and pyomelanin are two types of nitrogen-free<unk> . In the human skin, melanogenesis is initiated by exposure to UV radiation, causing the skin to darken.<unk>  is an effective absorbent of light; the pigment is able to dissipate over 99.9% of absorbed UV radiation. Because of this property,<unk>  is thought to protect skin cells from UVA, UVB radiation damage, reducing the risk of folate depletion and dermal degradation, and it is considered that exposure to UV radiation is associated with increased risk of malignant melanoma, a cancer of melanocytes<unk>  cells). Studies have shown a lower incidence for skin cancer in individuals with more concentrated<unk> , i.e. darker skin tone. However, the relationship between skin pigmentation and photoprotection is still uncertain.
Melanin
Ophanin
Respiratory pigment
Cellulite
Hematoporphyrin
Kerion
Neurite
Smegma