Melanocyte

Melanocytes are cells located in the bottom layer of the skin's epidermis[?]. They produce melanin, a pigment in the skin, eyes, and hair. In Caucasian people, melanocytes are triggered by ultraviolet rays, thus they have to be in the sunlight to tan. In other people, the melanocytes constantly produce melanin.

The typical density of melanocytes is between 1000 and 2000 cells per square millimeter of skin. The difference between fair people and dark people is not the amount of melanocytes, but how active the melanocytes are.

Albinos lack an enzyme, tyrosinase[?], that is required for melanocytes to produce melanin.