Hence, obesity-associated changes in gene expression of GHR, IGF-1 or IGFBP-3 in AT and/or excess AT mass may contribute to alterations in circulating levels of these growth-related factors, however so far, there is no study investigating the associations between gene expression in AT cells and serum levels of these factors in children. The gene discussed is IGF1; the disease is obesity due to melanocortin 4 receptor deficiency.