In this book, the authors discuss the genetics, geographic variation and disorders associated with skin pigmentation. Topics include the melanocortin-1 receptor as a key melanoma risk determinant and a critical regulator of the UV DNA damage repair response; three major signaling pathways involved in the establishment of mammalian skin and hair coloration via the regulation of tyrosinase activity; multiple genes and diverse hierarchical pathways that affect human pigmentation; acquired skin pigmenation; the pro-opiomelanocortin (POMC) and melanocortin systems in the regulation of human skin pigmentation; and an overview on the melanocyte precursor migration from neural cres.