FNDC5 and type 1 diabetes mellitus: Our previous study has shown that aerobic exercise training activates AMPK by increasing peroxide proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α), fibronectin type III domain-containing protein 5 (FNDC5), and uncoupling proteins (UCPs), suggesting that these AMPK signaling pathways improve insulin resistance and glucose intolerance in STZ-induced T1DM rats [12].