The P144L mutation also causes iron deposition in the cells, similarly to what has been reported in ISCU myopathy (Kollberg et al. 2009; Olsson et al. 2008), in agreement with the role of FDX2 in cellular iron homeostasis via its mitochondrial role in the maturation of cytosolic IRP1 to an aconitase. The gene discussed is FDX2; the disease is hereditary myopathy with lactic acidosis due to ISCU deficiency.