The changes in the expression of these inflammatory cytokines or chemokines recruit monocytes and neutrophils to migrate to infection, injury, and necrosis sites to engulf pathogens, inducing local inflammatory response, and even promoting the activation of dendritic cells and neutrophils; this series of chain reactions triggered by IL-1 will eventually help the host to resist the invasion of pathogens and maintain the homeostasis in the host’s intestine [40,41,42]. The gene discussed is IL1B; the disease is infection.