BDNF and obesity due to melanocortin 4 receptor deficiency: Visceral and subcutaneous LECs displayed an obesity-associated upregulation of the RAGE pathway, integrins and ECM–receptor interactions, while a downregulation in the brain-derived neurotrophic factor (BDNF), interleukin-5 (IL-5), IL-2 and AP1 networks was observed (Extended Data Fig. 3k,l).