Erythropoietic protoporphyria (EPP; OMIM # 177000) is a rare autosomal recessive disorder (1), that is caused by deficiency in the heme biosynthesis enzyme ferrochelatase (FECH, EC 4.99.1.1) (Figure 1A) (2,3). This evidence concerns the gene FECH and erythropoietic protoporphyria.