IGF1 and obesity due to melanocortin 4 receptor deficiency: Despite their obesity, we found increased levels of growth hormone (GH) mRNA and protein in the pituitary, as well as increased insulin-like growth factor 1 (IGF-1) protein levels in the liver and plasma of Sim1-cre;mir-7fl/fl mice compared to mir-7fl/fl controls (Fig. 3c–f).