TNF and obesity due to melanocortin 4 receptor deficiency: The migration of these monocytes is more vigorous in individuals with obesity; however, animal studies have demonstrated that GLP-1 causes a decline in the infiltration of macrophages within adipose tissue [66] and reduces the production and expression of pro-inflammatory cytokines, such as interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), and MCP-1 [67].