MIR378A and obesity due to melanocortin 4 receptor deficiency: Mir378 is encoded within a master metabolic regulator, the peroxisome proliferator-activated receptor γ coactivator 1β (PGC-1β), and mice lacking Mir378 were resistant to high-fat diet-induced obesity and exhibited enhanced mitochondrial fatty acid metabolism and elevated oxidative capacity of insulin-target tissues (56).