Melanin: a unifying theory of disease as exemplified by Parkinson's, Alzheimer's, and Lewy body dementia.Melanin, a ubiquitous dark pigment, plays important roles in the immune system, including scavenging reactive oxygen species formed in response to ultraviolet radiation absorption, absorbing metals, thermal regulation, drug uptake, innate immune system functions, redox, and energy transduction. 
THERM