Physical exertion and exercise are the primary defenses against obesity, insulin resistance, and diabetes. The transcriptional co-activator peroxisome proliferator-activated receptor C coactivator 1 (PGC-1), regulates mitochondrial biogenesis and function.1 Expression of the membrane protein Fibronectin type III domain-containing protein 5 (FNDC5) is stimulated in muscle by PGC-1 in response to exercise. FNDC5 is proteolytically clEAved and secreted as the hormone peptide irisin (named after the Greek goddess messenger Iris). Irisin has been shown to convert white adipose fat to brown adipose fat upon physical exertion. Brown adipose fat allows for mitochondrial uncoupling lEAding to thermogenetic programs and hEAt expenditure.2 The physiological responses induced by the effects of irisin have the potential to incrEAse weight loss and reduce insulin resistance and obesity.Technical InformationCAS Number9037-90-5SynonymsFibronectin Type III Domain 5FNDC5FRCP2PePPurity90% estimated by SDS-PAGESourcerecombinant protein expressed in E. coli. An N-terminal His-tag and SUMOpro tag were removed by clEAvage with SUMO protEAse 1 (Ulp1).Amino Acids1-111 (full-length, amino acids 32-143 of FNDC5)MW12.4 kDaLicenseSUMOpro tag was used under non-exclusive license from LifeSensors, Inc.UniProt Accession Q8NAU1