Cytokines produced by tumors can attract leukocytes together; in turn, leukocytes generate a series of cytokines, such as interleukin, tumor necrosis factor-alpha, interferon, etc. One of the most persuasive examples of the “relationship between inflammation and cancer” is that individuals with inflammatory bowel disease often later develop colorectal cancer (Herszenyi et al., 2015). This evidence concerns the gene TNF and colorectal cancer.