IL1B and obesity due to melanocortin 4 receptor deficiency: Importantly, obesity is associated with chronic low-grade inflammation [70, 71], and a high-fat diet increases the proinflammatory cytokines IL1-β, tumor necrosis factor alpha (TNF-α), C-reactive protein (CRP), and IL1-6 and stimulates inflammatory signaling in adipose, serum, liver, and brain [72–76].