Interleukin-6 (IL-6) can be considered an adipokine since it is released by adipocytes from obese individuals, which occurs in a size-dependent manner (i.e., larger adipocytes release greater amounts of IL-6) and links obesity to a state of low-grade inflammation (Skurk et al., 2007; Schuett et al., 2009). This evidence concerns the gene IL6 and obesity due to melanocortin 4 receptor deficiency.