AGER and obesity due to melanocortin 4 receptor deficiency: In particular, the circulating soluble form of the RAGE receptor (sRAGE) has been recently described as a marker of disease in different pathologies, ranging from cardiovascular disease to acute liver failure [19] and metabolic disorder in obesity and diabetes [5, 20], but the diagnostic role of sRAGE in osteoporosis has not been described so far.