IL18 and infection: Upon bacterial infection, macrophage recognizes the pathogen-associated molecular patterns (PAMP) through surface receptors for phagocytosis that subsequently secretes a series of cytokines to promote inflammation, such as IL-1β, IL-6, IL-18, IFN-γ, TNF-α, and IL-8, which subsequently recruits other types of immune cells to eliminate infection at the site of infection (Garcia-Weber et al., 2018; Jung et al., 2020).