The administration of 5-ALA to healthy mice activate their mitochondrial respiratory function by increasing the protein expression and activity of cytochrome c oxidase (complex IV).[6] In addition, Shimura et al. recently reported that 5-ALA/SFC increased the oxygen consumption rate and ATP level via an oxidative phosphorylation protein's expression induced by upregulations of heme, heme oxygenase-1, and the mtDNA copy number in skin fibroblasts from individuals with mitochondrial disease.[17]. This evidence concerns the gene HMOX1 and mitochondrial disease.