CD4 and hepatocellular carcinoma: Interestingly, levels of circulating and infiltrating HBV-specific CD8+ T cells were largely similar in HBV-associated HCC compared with CHB, whereas infiltrating CD4+ T cells and Tregs were significantly elevated in HBV-associated HCC, indicating that CD4+ T-cell populations may be a dominant factor in the progression of CHB to HBV-associated HCC.