The translation of ALAS2 depends on iron availability through the presence of an IRE in the gene 5′-untranslated region (5′-UTR): in a setting of iron deficiency, IRPs bind to the IRE, inhibiting ALAS2 translation [41,42], even though this mechanism may be by-passed in the terminal steps of erythropoiesis (see Section 3.3) [22]. The gene discussed is ALAS2; the disease is nutritional disorder.