For instance, melatonin treatment ameliorated lipid profile in patients with metabolic syndrome (Koziróg et al., 2011), reduced fat mass and increased lean mass in postmenopausal women (Amstrup et al., 2016), and enhanced the activation of insulin signaling pathways through melatonin receptors in diabetes (Karamitri & Jockers, 2019). This evidence concerns the gene INS and metabolic syndrome.