NAMPT and obesity due to melanocortin 4 receptor deficiency: Visfatin, a protein hormone with insulin-l ike effects mainly produced by adipocytes and macrophages, plays a key role during inflammatory processes.26 Plasma levels of visfatin are raised in several diseases: for example, type 2 diabetes, obesity, metabolic syndrome, atherosclerosis, cancer, rheumatoid arthritis and sepsis.27–31 Visfatin exhibits inflammatory properties by inducing the production of IL-1β, TNF-α, and IL-6 by monocytes and upregulating IL-6 gene expression in human endothelial cells.26,32