IL6 and obesity due to melanocortin 4 receptor deficiency: For example, a number of recent investigations have indicated the important relationship between the particular steps of colorectal cancer development and inflammation due to obesity, which is mediated by proinflammatory cytokines (e.g., interleukin-6 (IL-6)) and tumor necrosis factor-α (TNF-α) secreted by macrophages [2, 3].