TLR4 and hepatocellular carcinoma: In a recent study, researchers demonstrated that neutrophils promote hepatocellular carcinoma metastasis through the enhanced formation of NETs [33], which trigger a tumorous inflammatory response via the activation of the Toll-like receptors 4/9-cyclooxygenase 2 (TLR4/9-COX-2) axis, thereby fueling metastasis [34].