The alpha-MSH analog NDP-alpha-MSH [Nle4, D-Phe7], also known as Melanotan-1 or afamelanotide (MT-I), is a synthetic peptide that induces skin pigmentation [48] and has been approved in Europe for treating erythropoietic protoporphyria (EPP), a skin disease involving phototoxicity which can be ameliorated by inducing skin pigmentation. Here, POMC is linked to erythropoietic protoporphyria.