As in aging, fat tissue adipogenic transcription factor expression is decreased in obesity, and inflammatory mediators, including TNFα and IL-6, are increased (Nadler et al., 2000; Xu et al., 2002; Weisberg et al., 2003; Xu et al., 2003; Nair et al., 2005; Jerschow et al., 2007). Here, TNF is linked to obesity due to melanocortin 4 receptor deficiency.