IL1B and obesity due to melanocortin 4 receptor deficiency: Obesity-associated inflammation, including enhanced expression of interleukin 1 beta (IL1β), tumor necrosis factor alpha (TNFα), and IL6 in the hypothalamus, was first reported in 2005 (De Souza et al. 2005), and many investigators have since replicated this finding (Cai & Liu 2011, Thaler et al. 2013).