The pan-agonist afamelanotide ([Nle4,D-Phe7]-αMSH) (41) is approved by the European and U.S. regulatory administrations for the treatment of phototoxicity associated with erythropoietic protoporphyria (42), yet it is not selective and may potentially produce undesired side effects altering the other physiological roles of MC3-5 receptors. This evidence concerns the gene STAMBP and erythropoietic protoporphyria.