TNF and hepatitis B virus infection: There are few studies on cytokine production profile in occult hepatitis B patients and the mechanism of liver injury due to OBI is still unclear, but some studies describe that the persistence and transcription of HBV cccDNA in hepatocytes can lead to the production of cytokines, such as TNF-α and INF-γ, which can result in damage for hepatocytes [59, 60].