Recent studies have identified mitochondrial-derived peptides (MDPs) that are coded from the mtDNA.13, 14, 15 The first MDP, Humanin, is a 24-amino acid polypeptide that was discovered while screening cDNA libraries from brain of a patient with Familial Alzheimer’s Disease. This evidence concerns the gene MT-RNR2 and early-onset autosomal dominant Alzheimer disease.