no melanin is pigement go reasearch it. And melanin cancer is the disorder.

In humans, melanin is found in skin, hair, the pigmented epithelium underlying the iris, the medulla and zona reticularis of the adrenal gland, the stria vascularis of the inner ear, and in pigment bearing neurons of certain deep brain nuclei such as the locus ceruleus and the substantia nigra. Melanin is the primary determinant of human skin color.