S100A9 and hepatocellular carcinoma: In a controlled study involving hepatitis B virus (HBV)—infected individuals, researchers observed elevated levels of NETs in serum and tissue specimens from hepatocellular carcinoma patients infected with HBV and concluded that the HBV-mediated S100A9-TLR4/RAGE-ROS cascade facilitates the growth and metastasis of hepatocellular carcinoma [36].