Finally, several polymorphisms in iron homeostasis genes have been identified as risk factors for AMD, such as the TF receptors (TFR1 and TFR2) genes [15], IRP1 and IRP2 genes [16], and the heme oxygenase-1 and -2 (HMOX1/2) genes [17]. The gene discussed is HMOX1; the disease is age-related macular degeneration.