FECH also known as Ferrochelatase is localized to the mitochondrion, where it catalyzes the insertion of the ferrous form of iron into protoporphyrin IX in the heme synthesis pathway. FECH plays a crucial role as the terminal enzyme in protoheme biosynthesis, catalyzing the insertion of ferrous iron into protoporphyrin IX, which is essential for the production of heme, a vital component of hemoglobin and various cytochromes. Defects in the FECH gene lead to erythropoietic protoporphyria (EPP), a dominantly inherited disorder characterized by photosensitivity and hepatobiliary complications. Nitric oxide-sensitive clusters within FECH suggest a potential role in cellular signaling related to oxidative stress, highlighting FECH′s importance in maintaining cellular homeostasis and function.