In a model of diet-induced obesity utilizing Wistar rats, melatonin treatment reduced serum insulin levels, homeostatic model assessment index and myocardial infarct volume, while increasing serum adiponectin levels and activating baseline myocardial extracellular signal-regulated kinases 42/44 (ERK 42/44), glycogen synthase kinase-3 beta (GSK-3 β), signal transducer and activator of transcription 3 (STAT-3), and Protein Kinase B (PKB/Akt) during reperfusion [27]. The gene discussed is STAT3; the disease is obesity due to melanocortin 4 receptor deficiency.