Moreover, 5-FU-induced intestinal mucositis increases the production of pro-inflammatory cytokines, such as tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and interleukin-6 (IL-6), which are the hallmarks of mucositis inflammation [3, 4] and responsible for initiating inflammation in response to tissue injury and infection during chemotherapy. The gene discussed is IL6; the disease is infection.