TLR4 and acute kidney injury: In a mouse model of IRI-induced AKI, S100A8/A9 activates the NF-κB signaling pathway by binding to TLR4 and promotes the infiltration of the proinflammatory cytokines IL-6, IL-1β, and TNF-α and the aggregation of macrophages and neutrophils, thereby exacerbating renal inflammation (157–159).