CD4 and viral hepatitis: CD4+ T lymphocytes, as helper T cells, play an important regulatory role in the body's immune response and inflammatory response, and Treg/Th17 is derived from the initial CD4+ T cells (Th0), which antagonize each other in differentiation and function, and is closely related to the inflammatory response, which is involved in the occurrence of viral hepatitis, cirrhosis, and acute or chronic liver failure [10–13].