TLR9 and acute kidney injury: Building upon these observations, Han et al. delineated the dualistic role of renal TLR-9 in I/R induced AKI, revealing that tubular TLR-9 activation exacerbates parenchymal damage through NF-κB-mediated inflammation and caspase-dependent apoptosis, whereas extra-tubular TLR-9 signaling paradoxically confers cytoprotection.