MOTS-c (mitochondrial open reading frame of the 12S rRNA type-c) is a 16-amino-acid peptide, MRWQEMGYIFYPRKLR, encoded by a short open reading frame within the mitochondrial 12S rRNA gene. It was reported in 2015 as a mitochondrial-derived peptide, following the earlier identification of humanin. Research to date is largely in mice and cell culture, covering metabolic homeostasis and insulin sensitivity, mitonuclear signalling under metabolic stress, physical capacity in ageing mice, T cell regulation in an autoimmune diabetes model, and antibacterial activity.