INS and obesity due to melanocortin 4 receptor deficiency: Contrary to obesity and type II diabetic mouse models, Pgc-1α mRNA does not change in the hearts of Akita mice[104], which are a monogenic model of type 1 diabetes wherein mutation in the insulin 2 gene leads to improper folding of the insulin protein, resulting in pancreatic toxicity, reduced β-cell mass, and reduced insulin secretion.